Patent Publication Number: US-9421546-B2

Title: Universal shelving system

Description:
This application is a Continuation of Provisional application No. 61/481,984, filed on May 3, 2011. 
    
    
     FIELD OF THE INVENTION 
     The present invention relates generally to the art of cleaning and decontamination, and more particularly, to an apparatus for cleaning, washing, sterilizing and disinfecting laboratory glassware. 
     BACKGROUND OF THE INVENTION 
     Glassware, such as volumetric flasks, beakers, test tubes and the like are commonly used in laboratories. After each use in a laboratory test or procedure, the glassware must be thoroughly cleaned to remove deposits which could contaminate materials that are subsequently contained in the glassware. Glassware is often cleaned manually with a brush. However, this manual procedure is generally undesirable because it requires considerable time and effort. 
     To minimize manual cleaning time, laboratory glassware washing machines have been developed. Known laboratory glassware washing machines operate analogous to household dishwashers wherein the glassware is placed on racks within the washing machine. More specifically, the glassware is inverted such that the mouth and the neck of the glassware is received on a spindle extending vertically from the rack. Typically, the racks are movable on shelves into and out of the washing chamber of the glassware washing machine. At least one spray arm is typically located beneath the rack to apply upwardly directed wash and rinse sprays for washing and rinsing the glassware. Such glassware washing machines typically include a drying cycle for drying the glassware with heated air circulated within the washing chamber of the glassware washing machine. Although this type of glassware washing machine effectively cleans and dries a variety of different types of glassware articles, it has some drawbacks. As will be appreciated, the glassware to be washed, namely, flasks, beakers, test tubes and the like, come in many different sizes and shapes. For example, test tubes are generally smaller in width and height as compared to beakers or flasks. In addition, graduated cylinders are manufactured to have a wide range of heights and diameters, and flasks and beakers typically have enlarged bottom portions requiring more room when being washed. 
     To maximize the number and type of glassware articles that can be washed at the same time during a washing cycle, it is known to provide washers having removable and replaceable shelf and rack systems. Washers with removable racks or shelves allow an operator to choose a rack designed to receive a particular size of glassware, or to remove shelves to allow taller, elongated glassware to be positioned on lower racks within the washing chamber of the washing machine. 
     For example, U.S. Pat. No. 6,571,812 to Lavoie et al. discloses a universal shelving system having a permanent lower shelf for supporting a plurality of removable racks and an upper shelf comprised of three (3) shelf sections, each of which can be removed from the washing chamber to allow the racks on the lower shelf to hold taller, larger glassware that would not normally fit within the space between the upper and lower shelves. The washing chamber disclosed in the aforementioned patent includes a generally U-shaped fluid conduit that extends along the back wall and side walls of the washing chamber to provide washing and rinsing fluids to the racks and articles to be washed on the upper shelf. The U-shaped fluid conduit is disposed at approximately the mid-level in the washing chamber, and includes openings that allow for attachment of the aforementioned shelf sections, that form the upper shelf, to the channel. The shelf sections, when attached to the U-shaped conduit, are in fluid communication with the washing and/or rinsing fluid that is circulated through the U-shaped fluid conduit by the washer. The fluid is then conveyed through the shelf sections into the racks wherein the washing or rinsing fluid is directed into to the spindles and to nozzles in the spindle that direct the fluid to the interior of the glassware. 
     The shelving system disclosed in U.S. Pat. No. 6,571,812 allows individual shelf sections to be removed from the upper shelf to facilitate taller and larger glassware to be placed on the lower rack and shelves. When a shelf section is removed from the upper shelf, flaps associated with the opening in the fluid conduit would generally close off the opening such that washing or rinsing fluid would not flow through the opening during a washing or rinsing cycle. 
     While the shelving system disclosed in U.S. Pat. No. 6,571,812 was an improvement over the then-existing prior art, the configuration and position of the U-shaped fluid conduit generally limited insertion and removal of racks into the washer to one side, i.e., the front face, of the washing apparatus. Still further, each shelf section was mountable within the washing chamber in only one, specific location. Still further, the U-shaped fluid conduit had a rectangular cross-section that created problems in draining fluid from the system after the washing and rinsing cycles. 
     The present invention provides an improved shelving system of the type heretofore described and provides a fluid distribution line disposed outside the washing chamber and shelf sections that are mountable on the side walls of the washing chamber such that racks that are supported on the shelf sections may be inserted and removed through the front face and back face of the washing apparatus. Still further, a shelving system according to the present invention provides a mounting structure wherein each of the shelf sections can be mounted to each of the side walls of the washing chamber. In addition, the shelving system includes fluid connections that allow for more accurate sealing between a fluid distribution line and the shelf sections, and between the shelf sections and racks supported thereon to provide a more fluid tight connection therebetween. 
     SUMMARY OF THE INVENTION 
     In accordance with a preferred embodiment of the present invention, there is provided a washer, comprising a washing chamber defined by a pair of side walls, a top wall and a bottom wall, the washing chamber having an opened front face and an opened back face. A first shelf assembly is mounted within the washing chamber having at least one shelf section for receiving and supporting articles to be cleaned during a washing operation. A second shelf assembly is mounted within the washing chamber vertically above the first shelf. The second shelf assembly is mounted to the side walls having at least two shelf sections, at least one of the at least two shelf sections being selectively removable from the washing chamber so that additional space may be provided for larger articles on one side of the first shelf, and so that articles may be inserted into or removed from the washing chamber through the front face or back face of the washing chamber. 
     An advantage of the present invention is a decontamination unit (washer) for washing laboratory glassware having a washing chamber and a plurality of shelves for receiving and supporting glassware articles to be cleaned. 
     Another advantage of the present invention is a decontamination unit (washer) as described above having an upper shelf and a lower shelf, wherein the upper shelf has at least two (2) shelf sections and at least one of the two shelf sections is removable from the decontamination unit (washer). 
     Another advantage of the present invention is a decontamination unit (washer) as described above wherein each of the shelves supports a plurality of rack assemblies that are each slidable into and out of the washing chamber. 
     A still further advantage of the present invention is a decontamination unit (washer) as described above wherein the rack assemblies are removable from the decontamination unit (washer). 
     Another advantage of the present invention is a decontamination unit (washer) as described above that allows for rack assemblies to be inserted through one side of the decontamination unit (washer) and removed through another side of the decontamination unit (washer). 
     A still further advantage of the present invention is a decontamination unit (washer) as described above having fluid connections that extend through opposing sides of the decontamination unit (washer), which fluid connections are attachable to the shelves and shelf sections. 
     Another advantage of the present invention is a decontamination unit (washer) as described above wherein the shelves, shelf sections and rack assemblies are fluidly connected to each other to allow washing and rinsing fluids to flow from the decontamination unit (washer) to the shelf system, and through the shelf system to spindles on the rack assemblies, when the rack assemblies and shelves are in position within the washing chamber. 
     A still further advantage of the present invention is a decontamination unit (washer) as described above wherein a fluid-tight connection is made between the side walls of the decontamination unit (washer) and the removable shelf sections, and between the removable shelf sections and the rack assemblies thereon when the rack assemblies are in proper alignment with the shelves within the washing chamber during a decontamination cycle. 
     A still further advantage of the present invention is a decontamination unit (washer) as described above wherein movable valve elements connect the decontamination unit (washer) to the shelves and shelf sections, and the shelf sections and shelves to the rack assemblies. 
     A still further advantage of the present invention is a decontamination unit (washer) as described above having a more fluid-tight seal between the decontamination unit (washer), shelves, shelf sections and rack assemblies that allows a pump that is part of the fluid distribution section of the decontamination unit (washer) to operate at lower speeds. 
     Another advantage of the present invention is a decontamination unit (washer) as described above which is less likely to leak when fluid is circulated from the decontamination unit (washer) circulation system to the shelves, the shelf sections and the rack assemblies. 
     A still further advantage of the present invention is a decontamination unit (washer) as described above that utilizes round tubing to reduce retention of water in the circulation system when the circulation system is drained after a washing or rinsing cycle. 
     Another advantage of the present invention is a decontamination unit (washer) as described above which is less likely to retain fluid in lines between operating cycles and is thus able to improve rinsing of the articles within the decontamination unit (washer). 
     A still further advantage of the present invention is a decontamination unit (washer) as described above that allows better draining of fluid lines between operating cycles by reducing fluid retained in the fluid lines. 
     A still further advantage of the present invention is a decontamination unit (washer) as described above wherein shelving sections can easily and quickly be removed from the washing chamber to accommodate larger glassware within the washing chamber. 
     These and other advantages will become apparent from the following description of a preferred embodiment taken together with the accompanying drawings and the appended claims. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The invention may take physical form in certain parts and arrangement of parts, a preferred embodiment of which will be described in detail in the specification and illustrated in the accompanying drawings which form a part hereof, and wherein: 
         FIG. 1  is a front, perspective view of a decontamination unit (washer) showing a front door disposed in the front side of the decontamination unit (washer) in an opened position to show an interior washing chamber, and a rack assembly removed from the washing chamber; 
         FIG. 2  is a partially-sectioned, elevational view of the decontamination unit (washer) shown in  FIG. 1 , showing the decontamination unit (washer) positioned within a wall to isolate a front side of the decontamination unit (washer) from a back side of the decontamination unit (washer); 
         FIG. 3  is a partially-sectioned, front view of the decontamination unit (washer) shown in  FIG. 1 , showing a shelving system having an upper shelf comprised of a plurality of shelf sections within the washing chamber of the decontamination unit (washer), and schematically showing a fluid circulation system connected to the shelving system; 
         FIG. 4  is a partially-sectioned, front view of the decontamination unit (washer) shown in  FIG. 1 , showing a shelf section removed from the washing chamber to re-configure the shelving system to accept different sized glassware within the washing chamber; 
         FIG. 5  is a perspective view of a shelf section used within the washing chamber of the decontamination unit (washer), and an exploded view of a mounting/connection assembly for mounting the shelf section within the decontamination unit (washer); 
         FIG. 6  is a perspective view of a removable rack assembly that is used on the shelves and shelf sections of the decontamination unit (washer) to hold glassware articles to be washed; 
         FIG. 7  is an enlarged, cross-sectional view of a removable shelf section mounted within the washing chamber having a rack assembly mounted thereto, showing how fluid flows from a fluid manifold within the decontamination unit (washer) through the shelf section and the rack assembly; 
         FIG. 8  is a view of the removable shelf section shown in  FIG. 7  with the rack assembly removed therefrom; 
         FIG. 9  is an enlarged view of the mounting/connection assembly for mounting a shelf section to the side wall of the washing chamber, showing the position of a valve piston during an operating cycle when a shelf section is not attached to the mounting/connection assembly; 
         FIG. 10  is a sectional view taken along lines  10 - 10  of  FIG. 7 , showing a wheel on a rack assembly positioned within a rectangular notch formed in a track of a shelf section for locating the rack assembly on the shelf section during an operating cycle; 
         FIG. 11  is a sectional view through a fluid conduit having a circular cross-section illustrating the amount of residual fluid that may remain within the fluid conduit following an operating cycle; and 
         FIG. 12  is a cross-sectional view of a fluid conduit having a rectangular cross-section illustrating the amount of fluid that may remain within such a fluid conduit following an operating cycle. 
     
    
    
     DETAILED DESCRIPTION OF PREFERRED EMBODIMENT 
     Referring now to the drawings wherein the showings are for the purpose of illustrating a preferred embodiment of the invention only and not for the purpose of limiting same,  FIG. 1  shows a decontamination unit (washer)  10 , illustrating a preferred embodiment of the present invention. Decontamination unit (washer)  10  is generally comprised of an outer housing  22  that defines the exterior of decontamination unit (washer)  10  and an inner housing  42  that defines a washing chamber  60 . Outer housing  22  has a front wall  24 , a back wall  26 , two side walls  32 ,  34  and a top wall  36 . As illustrated in the drawings, outer housing  22  is generally rectangular in shape. 
     Inner housing  42  (best seen in  FIGS. 3 and 4 ) is comprised of two spaced-apart side walls  44 ,  46 , a top wall  52  and a bottom wall  54 . Walls  44 ,  46 ,  52 ,  54  of inner housing  52  extend from front wall  24  of outer housing  22  to back wall  26  of outer housing  22 . Together, outer housing  22  and inner housing  42  define a decontamination unit (washer) chamber  60  having a first opening  62  formed in front wall  24  of outer housing  22  and a second opening  64  formed in back wall  26  of outer housing  22 . Vertical slots  66  are formed in outer housing  22  along the sides of openings  62 ,  64  in front wall  24  and back wall  26  of outer housing  22 . Flat, rectangular doors  72 , having windows  74  formed integrally therewith, are designed to reciprocally slide vertically in slots  66  between an opened position that allows access to washing chamber  60 , and a closed position that closes washing chamber  60  during operation. 
     In the drawings, decontamination unit (washer)  10  is shown disposed within a wall or partition  12  (shown in phantom lines in  FIG. 1 ) on a floor  14 . In such a configuration, first opening  62  in front wall  24  of outer housing  22  would be disposed in a “dirty” room or space  16 , and second opening  64  in back wall  26  of outer housing  22  would be disposed in a “clean” room or space  18 , as shall be discussed in greater detail below. 
     As best seen in  FIGS. 3 and 4 , washing chamber  60  is generally rectangular in shape. Bottom wall  54  of inner housing  42  is tapered toward one side to define a sump  56  at the bottommost portion of washing chamber  60 . Sump  56  is connected to a heater  82  that is capable of heating fluids flowing therethrough. A fluid line  84  connects the outlet of heater  82  to an inlet of a pump  86 . In accordance with the present invention, pump  86  is preferably a two-speed pump. The outlet of pump  86  is connected to a fluid distribution circuit  92 . Fluid distribution circuit  92  is basically comprised of a fluid distribution line  94  that forms a closed loop. Fluid distribution line  94  vertically surrounds inner housing  42  and washing chamber  60 , but is disposed within outer housing  22 . Spray arms  95 , disposed within washing chamber  60  beneath top wall  52 , are connected to fluid distribution line  94 . 
     A branch line  94   a  from fluid distribution line  94  extends through bottom wall  54  of inner housing  42  into washing chamber  60  and connects to a fluid feeder line having three (3) fluid connectors  98 , that shall be described in greater detail below. Fluid distribution line  94  is also in fluid communication with two, spaced-apart mounting/connection assemblies  220  that extend through side walls  44 ,  46  of inner housing  42  into washing chamber  60 . In the embodiment shown, mounting/connection assemblies  220  are generally axially aligned with each other, and are disposed at the same level within washing chamber  60 . Mounting/connection assemblies  220  are preferably disposed midway between openings  62 ,  64  defined in front wall  24  and back wall  26  of outer housing  22 . In other words, mounting/connection assemblies  220  are essentially spaced near the middle of side walls  44 ,  46  of inner housing  42 . 
     A detergent dispenser  88  is connected to fluid line  84  near the inlet of pump  86  to provide detergent to be mixed with heated water flowing through pump  86 . A valve  76  in line  78  connecting detergent dispenser  88  to the inlet of the pump controls dispensing of detergent into fluid distribution circuit  92 . A controller (not shown) controls the overall operation of decontamination unit (washer)  10  as is conventionally known. A drain line  87  that is connected to fluid line  84  between heater  82  and pump  86  facilitates draining of fluid distribution circuit  92  during different operating cycles, i.e., washing and rinsing of decontamination unit (washer)  10 . A valve  89  within drain line  87  controls flow therethrough. 
     As best seen in  FIGS. 1 through 4 , decontamination unit (washer)  10  includes a shelving system  110  comprised of a lower shelf assembly  120  and an upper shelf assembly  140  that are disposed horizontally within washing chamber  60 . In the embodiment shown, each shelf assembly  120 ,  140  is designed to hold three (3) removable rack assemblies  250  that, in turn, hold the glassware “G” or articles to be washed. 
     Lower shelf assembly  120 , preferably a rigid, non-removable structure, is basically comprised of transverse horizontal beams (not shown) that are disposed in parallel relationship to each other and that span side walls  44 ,  46  of washing chamber  60 . These transverse beams support two spaced-apart, generally C-shaped rails  122  that are disposed near side walls  44 ,  46 , as best seen in  FIGS. 3 and 4 . These C-shaped rails  122  define inwardly facing channels and the lower legs of the C-shaped rails  122  define tracks, which shall be described in greater detail below. Disposed between two C-shaped rails  122  are two spaced-apart intermediate rail members  124  that are parallel to C-shaped rails  122 . Intermediate rails  124  also define channels and further define tracks for receiving the removable rack assemblies  250 , as shall be described in greater detail below. C-shaped rails  122  and intermediate rails  124  effectively divide lower shelf assembly  120  into three, equally sized rack assembly receiving stations, designated  126 A,  126 B,  126 C in the drawings. As illustrated in  FIGS. 3 and 4 , the three fluid connectors  98  connected to fluid feeder lines  96  are disposed to be centrally located beneath the three rack assembly receiving stations  126 A,  126 B,  126 C defined by rails  122 ,  124  on lower shelf assembly  120 . 
     In the embodiment shown, upper shelf assembly  140  is comprised of a first shelf section  142  and a second shelf section  144 . First shelf section  142  is designed to define a single rack assembly receiving station  146 A and to support a single, removable rack assembly  250 . Second shelf section  144  is designed to define two rack assembly receiving stations  146 B,  146 C and to support two removable rack assemblies  250 . First shelf section  142  and second shelf section  144  are similar in construction. Therefore, only first shelf section  142  shall be described in detail, it being understood that such description and the basic construction described applies also to second shelf section  144 . 
     Referring now to  FIG. 5 , first shelf section  142  is best seen. As shown in the drawings, first shelf section  142  is generally comprised of a rectangular frame  152  having inward-facing C-shaped sides  154 . A lower flange of each C-shaped side  154  defines an elongated roller support surface or track  156 . Three, spaced-apart rectangular notches  158  are formed in each roller support surface  156 . The longitudinal ends of frame  152  include downward extending panels  162  having elongated apertures  164  formed therein to define a hand grip  166  along the lower edge of each panel  162 . Aperture  164  in panels  162  are preferably large to allow fluids sprayed within washing chamber  60  to pass therethrough. Attached to the underside of rectangular frame  152  is a fluid distribution manifold  172 . In the embodiment shown, fluid distribution manifold  172  is comprised of cylindrical, tubular piping. Fluid distribution manifold  172  has a tubular, main conduit  174  that traverses the underside of rectangular frame  152 . A fluid connection housing  176  is disposed in the center of main conduit  174 . Fluid connection housing  176  is generally cylindrical in shape and has a closed bottom end  176   a  and an opened upper end  176   b , as best illustrated in  FIG. 8 . Fluid connection housing  176  defines a cylindrical inner cavity  178 . The lower half of fluid connection housing  176  is attached to main conduit  174  such that cavity  178  is in fluid communication with an inner passageway  174   a  through main conduit  174 . A generally square fluid circuit  182 , formed of tubular pipe, intersects the ends of main conduit  174 . A passageway  182   a  defined by square fluid circuit  182  communicates with passage  174   a  of main conduit  174 . In this respect, passageways  174   a ,  182   a  through main conduit  174  and square fluid circuit  182  are fluidly connected to each other. As shown in the drawings, one end of main conduit  174  is closed and the other end is attached to a mounting sleeve  184 . Mounting sleeve  184  has an opening  184   a  formed therethrough to communicate with passageway  174   a  through main conduit  174 . Mounting sleeve  184  is generally comprised of a flat plate having the shape of an isosceles trapezoid. The tapered sides of the plate are bent forward, i.e., wrapped around, to define inner slots  186  along the sides of the plate, as best seen in  FIG. 5 . 
     Fluid connection housing  176  is generally disposed within the center of frame  152 . Inner cavity  178  of fluid connection housing  176  is dimensioned to receive a piston  192 , as best seen in  FIGS. 7 and 8 . Fluid connection housing  176  includes an inwardly extending annular wall  194  within cylindrical inner cavity  178  which maintains piston  192  in the upper end of inner cavity  178  of fluid connection housing  176 . As shown in  FIGS. 7 and 8 , the lower portion of inner cavity  178  communicates with passage  174   a  through main conduit  174 . The upper portion of cylindrical inner cavity  178  receives piston  192  therein. Piston  192  is generally cup-shaped and has a cylindrical side wall  192   a  and a generally flat top wall  192   b . An aperture  196  extends through top wall  192   b  of piston  192 . An annular slot  192   c  is formed in the outer surface of side wall  192   a . Slot  192   c  is dimensioned to receive an annular gasket  198  therein. Small apertures  199  extend through side wall  192   a  to communicate with slot  192   c  in the side wall and with the underside of gasket  198 . As shown in  FIGS. 7 and 8 , piston  192  is disposed within inner cavity  178  with the opened end of piston  192  facing downward toward the bottom of inner cavity  178  and passage  174   a  of main conduit  174 . 
     Referring now to  FIG. 5 , square fluid circuit  182  includes leg sections  182   b ,  182   c . Leg sections  182   b ,  182   c  are generally parallel to main conduit  174 . On the undersides of these leg sections  182   b ,  182   c , rotatable spray arms  212  are mounted. Spray arms  212  include apertures  214  directed upwardly to the underside of frame  152 . 
     Second shelf section  144  is similar to first shelf section  142 , as described above, but is essentially twice as wide. Basically, to form second shelf section  144 , two first shelf sections  142 , are placed side-by-side. A bridging portion connects end panels  162  of the adjacent shelf sections. An elongated main conduit  174 ′ is extended to fluidly connect the fluid distribution manifolds  172  of the side-by-side shelf sections together. As will be appreciated, only one end of the elongated main conduit  174 ′ has a mounting sleeve thereon. The other end of elongated main conduit  174 ′ is closed. Each of the two joined sections has a fluid connection housing  176  and piston  192  connecting to a rack assembly  250 . In other words, second shelf section  144  is dimensioned to receive and support two rack assemblies  250 . 
     First shelf section  142  and second shelf section  144  are each dimensioned to be mounted to (and to be removable from) a mounting/connection assembly that is fluidly connected to fluid distribution line  94  and that extends through either side wall  44 ,  46  of inner housing  42 . Mounting/connection assembly  220  that extends through side walls  44  of inner housing  42  is essentially identical to mounting/connection assembly  220  that extends through side wall  46 , and therefore, only one shall be described in detail. In this respect, a mounting/connection assembly  220  is basically comprised of an enclosure  222  defining a cavity  224  that is in fluid communication with passageway  94   a  in fluid distribution line  94  that surrounds washing chamber  60 . Enclosure  222  has a closed end and an opened end. Cavity  224  has a first portion in fluid communication with passageway  94   a  through fluid distribution line  94  and a second portion at the opened end of enclosure  222 . The second portion of cavity  224  has a cylindrical inner surface  224   a  dimensioned to receive a fluid piston  226 , as best seen in  FIG. 5 . An inwardly extending annular wall  228  defines a seat  229  for fluid piston  226 . A plate  231  extends outwardly from the free end of enclosure  222 . Plate  231  is essentially a flat plate having the shape of an isosceles trapezoid, as best seen in  FIG. 5 . Plate  231  is oriented such that the parallel sides of the plate are arranged horizontally. Plate  231  is dimensioned to be received within mounting sleeve  184  wherein the side edges of plate  231  are captured in slots  186  of mounting sleeve  184 . 
     Referring now to  FIG. 9 , fluid piston  226  is generally cylindrical in shape and has a flat bottom wall  226   a  and a cylindrical side wall  226   b  extending to one side thereof. A fluid opening  232  is formed through bottom wall  226   a  of piston  226 , and an annular groove  226   c  is formed in the outer surface of side wall  226   b . Annular groove  226   c  is dimensioned to receive a J-shaped gasket member  233  therein. Apertures  234  are formed through bottom wall  226   a  to communicate with annular groove  226   c  and the underside of J-shaped gasket member  233 . 
     A pin or post  242  is attached to bottom wall  222   a  of enclosure  222 . Pin  242  extends through cavity  224  of enclosure  222 . A resilient polymer stop  244  is attached to the free end of post  242 . Stop  244  has a conical body portion  244   a  and a flat, annular flange portion  244   b  extending outwardly therefrom. Flange portion  244   b  is dimensioned to engage the inner surface of bottom wall  226   a  of fluid piston  226  and to limit movement thereof. Stop  244  is attached to the free end of post  242  by a conventional fastener  246  such that piston  226  is captured within cavity  224  of enclosure  222  between seat  229  and stop  244 . Stop  244  basically maintains piston  226  within cavity  224  of enclosure  222  and limits movement of piston  226  relative thereto. As best seen in  FIGS. 5 and 6 , fluid opening  232  through bottom wall  226   a  of piston  226  is larger than the outer dimensions of post  242  so as to allow fluid to flow around stop  244  and through opening  232  defined in bottom wall  226   a  when bottom wall  226   a  of piston  226  is not in contact with annular flange portion  244   b  of stop  244 . The free end of side wall  226   b  of piston  226  is tapered to form a conical-shaped end, as best seen in  FIG. 9 . By way of example, not limitation, piston  226  may be formed of Teflon or stainless steel. 
     Referring now to  FIG. 6 , removable rack assembly  250  is best seen. Rack assembly  250  is essentially comprised of an elongated metal strip that is formed into a rectangular frame  252 . A manifold pipe  254  traverses frame  252  and is secured to the sides of frame  252 . Manifold pipe  254  is closed at both ends, but defines a central passageway  254   a  therethrough. A central hub  256  is disposed in manifold pipe  254  at the midsection thereof. Central hub  256  is basically a cylindrical cup-shaped element having a closed upper end and an opened lower end having a flat edge. Hub  256  defines a cylindrical cavity  258  on the underside thereof. Cavity  258  is in fluid communication with passageway  254   a  extending through manifold pipe  254 . Fluid distribution conduits  262  extend from manifold pipe  254  to the longitudinal ends of rectangular frame  252 . In the embodiment shown, distribution conduits  262  are cylindrical pipes having one end attached to manifold pipe  254  and the other end attached to the longitudinal ends of rectangular frame  252 . Distribution conduits  262  define fluid pathways  262   a  from passageway  254   a  in manifold pipe  254  to a plurality of spindles  266  that extend vertically upward from distribution conduits  262 . As best seen in  FIGS. 6 and 7 , pluralities of spaced-apart spindles  266  extend generally perpendicular to the plane of frame  252 . Spindles  266  are essentially hollow tubes that are in fluid communication with pathways  262   a  through distribution conduits  262 . Apertures  268  are formed in spindles  266  and are dimensioned to allow fluid flowing through manifold pipe  254 , fluid distribution conduits  262  and spindles  266  to generate directional sprays of fluid. 
     A generally U-shaped handle  272  is attached to each end of frame  252 . Three, spaced-apart rollers  274  are attached to each side of rectangular frame  252 . Rollers  274  are positioned on frame  252  to allow rack assemblies  250  to roll upon a flat surface. In this respect, rack assemblies  250  are dimensioned such that rollers  274  may roll upon the roller support surface  156  defined by C-shaped sides  154  of shelf sections  142 ,  144 , as best illustrated in  FIG. 7 . Rollers  274  mounted to frame  252  of rack assemblies  250  are spaced-apart such that they interact with notches  158  of roller support surfaces  156 . In this respect, notches  158  are located relative to fluid connection housings  176  on shelf sections  142 ,  144  such that when rollers  274  on a rack assembly  250  are disposed within notches  158 , as illustrated in  FIG. 7 . A central hub  256  on a rack assembly  250  is in registry with a fluid connection housing  176  on shelf sections  142  or  144 , and the lower flat edge of hub  256  is above top wall  192   b  of piston  192 , as illustrated in  FIG. 7 . The components heretofore described, namely, shelving system  110 , rack assemblies  250  and mounting/connection assembly  220  are preferably formed of a non-corrosive metal, such as, by way of example and not limitation, stainless steel. 
     Referring now to the operation of decontamination unit (washer)  10 , first and second shelf sections  142 ,  144  are designed to be mounted to mounting/connection assemblies  220  on the side walls  44 ,  46  of inner housing  42  that defines washing chamber  60 . In accordance with one aspect of the present invention, since mounting sleeve  184  on the sides of first shelf section  142  and second shelf section  144  are identical, and mounting plate  231  on mounting/connection assemblies  220  are identical, first shelf section  142  and second shelf section  144  can be mounted to either side of washing chamber  60 . 
     When mounted to mounting/connection assembly  220 , shelf sections  142 ,  144  assume a position best illustrated in  FIG. 8 .  FIG. 8  shows first shelf section  142  mounted onto side wall  44  of inner housing  42 . In this position, turned ends of mounting sleeve  184  on first shelf section  142  rests upon the sloping sides of mounting plate  231  of mounting/connection assembly  220 . In similar respects, second shelf section  144  would be attached, if desired, to mounting/connection assembly  220  on the opposite side wall  46  of inner housing  42 . With both first and second shelf sections  142 ,  144  attached to inner housing  42 , lower and upper shelf assemblies  120 ,  140  would assume a configuration as illustrated in  FIGS. 1 and 3 . ( FIG. 4  illustrates a configuration where only first shelf section  142  is attached to mounting/connection assembly  220  on side wall  44  of inner housing  42 ). As noted above, removable rack assemblies  250  are dimensioned to be received on a shelf assembly  120 ,  140 . Lower shelf assembly  120  is dimensioned to receive three (3) removable rack assemblies  250 . First shelf section  142  of upper shelf assembly  140  is dimensioned to receive one rack assembly  250 , and second shelf section  144  of upper shelf assembly  140  is dimensioned to receive two rack assemblies  250 . 
     Rollers on rack assemblies  250  allow rack assemblies  250  to be rolled into position relative to lower shelf assembly  120  and first and second shelf sections  142 ,  144  of upper shelf assembly  140 . In this respect, as indicated above, rectangular notches  158  on roller support surfaces  156  of rectangular frame  152  of shelf sections  142 ,  144  are positioning means wherein rollers  274  on rack assemblies  250  fall into rectangular notches  158  and locate rack assemblies  250  in a predetermined position relative to a shelf section  142  or  144 . Specifically, rack assemblies  250  are positioned on the lower shelf assembly  120  and a first and second shelf section  142 ,  144  such that a central hub  256  on a rack assembly  250  is positioned immediately above a fluid connection housing  176  on the lower shelf assembly  120  or on the first or second shelf sections  142 ,  144 . As illustrated in  FIG. 4 , if second shelf section  144  is not inserted into washing chamber  60 , taller glassware “G” may be inserted into decontamination unit (washer)  10  and washed together with smaller glass articles in washing chamber  60 . In this respect,  FIG. 6  shows a rack assembly  250  with uniformly spaced spindles  266  of the same height. As will be appreciated, special rack assemblies (not shown) may be produced to have longer spindles  266  to accommodate taller or longer glass articles or the number of spindles  266  may be reduced and the spacing between spindles  266  increased for wider glassware “G,” such as flasks or beakers. Because a rack assembly  250  is easily removable from lower shelf assembly  120  and/or shelf sections  142 ,  144 , a rack assembly  250 , designed for specific types of glassware “G,” may be used during a single washing cycle. 
     During a washing or rinsing cycle, washing or rinsing fluid is conveyed through fluid distribution circuit  92  by pump  86 . In this respect, fluid is conveyed through fluid distribution line  94 , wherein the fluid is forced into enclosure  222  of each mounting/connection assembly  220 . Fluid forced into cavity  224  of enclosure  222  is forced against the underside of bottom wall  226   a  of fluid piston  226 . In this respect, the force of the fluid exerted on the underside of bottom wall  226   a  forces fluid piston  226  against the flat portion of mounting sleeve  184  on first shelf section  142 . As shown in  FIG. 7 , fluid piston  226  and mounting/connection assembly  220  are dimensioned such that when fluid piston  226  abuts mounting sleeve  184 , fluid is allowed to flow through opening  232  in bottom wall  226   a  of fluid piston  226 , around stop  244  and into main conduit  174  of first shelf section  142 . Fluid is also forced through apertures  234  in bottom wall  226   a  of piston  226  to the back side of J-shaped gasket  233 . As a result, J-shaped gasket  233  expands against the inner cylindrical surface of mounting/connection assembly  220  to form a seal therewith. 
     As a result, a quick connection and seal are formed between mounting/connection assembly  220  and first shelf section  142 . As a result of this connection, fluid is forced around the stop  244  and fills the main conduit  174  of fluid distribution manifold  172  on shelf section  142 . As main conduit  174  is filled, fluid eventually comes in contact with top wall  192   b  of piston  192  in fluid connection housing  176 . Because opening  196  through top wall  192   b  of piston  192  has a smaller cross-section than the passageway of main conduit  174 , a pressure build-up will occur against top wall  192   b  of piston  192 . The pressure on top wall  192   b  of piston  192  forces piston  192  in an upward direction against central hub  256  on rack assembly  250 . The weight of rack assembly  250  and the glassware “G” thereon maintains the lower, flat edge of central hub  256  against the upper surface of piston  192  thereby creating a seal between central hub  256  and piston  192 . Fluid flowing through aperture  199  in side wall  192   a  of piston  192  is forced into slot  192   c  and against the back side of gasket  198 . Gasket  198  is forced against the inner surface of fluid connection housing  176 , thereby forming a fluid seal between fluid connection housing  176  and piston  192 . 
     With seals formed between mounting/connection assembly  220  and shelf section  142 , and between shelf section  142  and rack assembly  250 , fluid from fluid distribution circuit  92  is forced into main pipe  254  of rack assembly  250  and into distribution conduits  262 , where it is forced up into spindles  266 . The fluid is then forced through apertures  268  in spindles  266  to convey either washing fluid or rinsing fluid to the interior portions of the glassware “G” mounted on spindles  266 . At the same time, fluid is forced to rotary spray arms  212  on the underside of first shelf section  142 , that, in turn, sprays fluid (either washing fluid or rinsing fluid) against the underside of rack assembly  250  and the glassware “G” thereon. 
     Because of the piston-type connections between shelf sections  142 ,  144  and sides  44 ,  46  of washing chamber  60 , and between shelf sections  142 ,  144  and rack assemblies  250 , fluid loss through these types of connections is minimal, as compared to prior assemblies. Reducing fluid loss through the fluid circuits to spindles  266  enables pump  86  within decontamination unit (washer)  10  to operate at a lower speed while maintaining better washing pressure at apertures  268  of spindles  266 . 
     When a washing cycle or rinsing cycle is completed, fluid is more easily drained from the disclosed structure because of the use of circular tubing and piping which retains less water and residual material within the piping system during a draining operation. 
     In the event that first shelf section  142  and/or second shelf section  144  are not inserted during an operating cycle, mounting/connection assembly  220  prevents fluid in fluid distribution line  94  from flowing into washing chamber  60 . 
     As illustrated in  FIG. 9 , in absence of a shelf section  142 ,  144  being mounted onto mounting plate  231  of mounting/connection assembly  220 , piston  226  moves toward the center of washing chamber  60 . In this respect, fluid pressure acting on the underside of bottom wall  226   a  of piston  226  forces piston  226  against annular flange portion  244   b  on stop  244 . As shown in  FIG. 9 , flange portion  244   b  operatively engages the inner surface of bottom wall  226   a  to effect a seal between stop  244  and bottom wall  226   a  of piston  226  thereby preventing fluid from being forced out from the fluid distribution line  94 . Fluid is still forced through apertures  234  in bottom wall  226   a  to the back side of gasket  233  to inflate gasket  233  against enclosure  222  of mounting/connection assembly  220 , to further facilitate a seal between piston  226  and enclosure  222 . Thus, when first shelf section  142  or second shelf section  144  of upper shelf assembly  140  is not inserted or mounted to washing chamber  60 , mounting/connection assembly  220  automatically seals itself to prevent fluid in fluid distribution line  94  from entering washing chamber  60  through mounting/connection assembly  220 . 
     Heretofore, the fluid connections between first shelf section  142  and second shelf section  144  and mounting/connection assembly  220  in washing chamber  60  have been discussed. In similar fashion, lower shelf assembly  120  includes a number of fluid connection housings  176  that are dimensioned to mate with hubs  256  on rack assemblies  250 , as heretofore described. In other words, when rack assemblies  250  are inserted in rack positions on lower shelf assembly  120 , pistons  192  in fluid connection housing  176  interact with hubs  256  on rack assemblies  250  to form a seal therebetween, as heretofore described. As will be appreciated from an understanding of the specification and the drawings, rack assemblies  250  need to be in position on each of the shelf locations or shelf sections  142 ,  144  to form a connection between shelf locations and shelf sections  142 ,  144  and rack assemblies  250  to prevent fluid from being forced from lower shelf assembly  120  or first and second shelf sections  142 ,  144  during operation of decontamination unit (washer)  10 . 
     It will be appreciated that because mounting/connection assembly  220  that connects the fluid distribution circuit  92  to first and second shelf sections  142 ,  144  are located on side walls  44 ,  46  of inner housing  42  that forms washing chamber  60 , front and back openings  62 ,  64  may be provided in front and back walls  24 ,  26  of washing chamber  60 . As a result, decontamination unit (washer)  10  can be utilized as part of a “dirty room” and a “clean room” facility wherein wall  12  divides a dirty room from a clean room, and wherein rack assemblies  250  containing dirty glassware “G” can be rolled into washing chamber  60  from dirty room  16  and, after a washing cycle, be removed through opening  64  in back wall  26  of decontamination unit (washer)  10  into clean room  18 . By arranging fluid distribution circuit  92  of decontamination unit (washer)  10  such that fluid distribution line  94  surrounds the top, sides and bottom of washing chamber  60 , openings  62 ,  64  in front and back walls  24 ,  26  of washing chamber  60  allow access into and out of washing chamber  60  from two directions. 
     The present invention thus provides a decontamination unit (washer)  10  and universal shelving system that allows greater access to and from washing chamber  60 , and at the same time allows each shelf section that comprises the upper shelf assembly  140  to be mounted in washing chamber  60  on either side of washing chamber  60 . Still further, the sealing arrangement between the fluid circulation system and the shelf sections and between shelf sections  142 ,  144  or shelf assembly  120  and rack assemblies  250  facilitates more accurate fluid sealing of the fluid circulation system thereby allowing pumps  86  to operate more efficiently and at lower speeds, yet provide greater washing pressure to articles (glassware) to be cleaned. 
     Still further,  FIGS. 10 and 11  schematically illustrate how use of conduits and pipes  282  having a circular cross-section retain less fluid between cycles as compared to pipes or conduits  284  having a rectangular cross-section. 
     The foregoing description is a specific embodiment of the present invention. It should be appreciated that this embodiment is described for purposes of illustration only, and that numerous alterations and modifications may be practiced by those skilled in the art without departing from the spirit and scope of the invention. It is intended that all such modifications and alterations be included insofar as they come within the scope of the invention as claimed or the equivalents thereof.