Abstract:
A valve for use in harsh chemical environments which is substantially inert from the predations of the chemicals. At least a valve insert is formed from ceramic. The insert defines potential fluid passageways while a gate determines flow path(s).

Description:
FIELD OF THE INVENTION  
         [0001]    The following invention is directed to valving used particularly in clinical and analytical laboratories for fluid distribution, for example, in syringe drivers, diluters, dispensers, and sampler valves such as “loop valves” in both automated and manual dispensing systems.  
         BACKGROUND OF THE INVENTION  
         [0002]    Many scientific laboratories, such as those in research, medical and industrial settings, distribute fluid through valves. Should the fluid react with the valve&#39;s components, the process is compromised. Presently, the industry standard requires the valve&#39;s gate to be custom made for primarily every job and application.  
           [0003]    The following prior art reflects the state of the art of which applicant is aware and is included herewith to discharge applicant&#39;s acknowledged duty to disclose the state of the art. It is stipulated, however, that none of these references teach singly nor render obvious when considered in any conceivable combination the nexus of the instant invention as disclosed in greater detail hereinafter and as particularly claimed.  
                                                       INVENTOR   PAT. NO.   ISSUE DATE                           Kish, Jr.   6,149,127   Nov. 21, 2000                      
 
         OTHER PRIOR ART REFERENCES  
         [0004]    Hamilton Company Brochure “OEM/Industrial Products”, June 1995, entire brochure.  
         SUMMARY OF THE INVENTION  
         [0005]    The following invention is directed to a valve whose internal moving component which diverts the fluid and seals the valve from leaking is in the form of a fluid passageway insert which is made from a ceramic that is substantially impervious and inert as to a vast, overwhelming majority of fluids. By ceramic it is understood to be a non metallic mineral fired at high temperatures. Such ceramics include the following properties: inertness, resistance to deformation and long wear. The ceramic insert is preferably formed from substantially pure aluminum oxide (90-99.5%) “alumina” mixed with additives required for processing. However, less pure compositions (e.g. 60% aluminum oxide) has utility. Such ceramic is available from Coorstek, Golden Colo. and LTD Ceramic, Newark, Calif. The key to the percentage of aluminum oxide involves the insert&#39;s sealing ability versus the resistance to rotating an overlying gate (friction torque).  
         OBJECTS OF THE INVENTION  
         [0006]    It is a primary object of the present invention to provide an improved valve which is not prone to pitting, galling, seizing, freezing, leaking, etc. in the face of a wide variety of fluids.  
           [0007]    A further object of the present invention is to provide a valve as characterized above which is standardized to allow substitution of components from inventory, especially the valve&#39;s disc gate and insert which heretofore required custom fabrication for specific jobs and environments.  
           [0008]    A further object of the present invention is to provide a valve as characterized above which is particularly tailored to solve chronic, long-standing problems involving valves in the setting of medical, clinical and analytical laboratories, for example.  
           [0009]    Viewed from a first vantage point, it is an object of the present invention to provide a valve for use in clinical, analytical or industrial laboratories, comprising, in combination: a housing having fluid inlet means and fluid outlet means, an insert interposed between the fluid inlet means and the fluid outlet means, the insert formed from ceramic material, and means to orient a gate adjacent the insert to control transfer of fluid between the inlet means and the outlet means, the ceramic insert substantially chemically inert to most fluids in the clinical, analytical or industrial laboratory.  
           [0010]    These and other objects will be made manifest when considering the following detailed specification when taken in conjunction with the appended drawing figures.  
       
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0011]    [0011]FIG. 1 is an exploded parts perspective of the valve in one form.  
         [0012]    [0012]FIG. 2 is an exploded parts perspective of the valve in a second form.  
         [0013]    [0013]FIGS. 3A and 3B show variations in housing, insert and disc gate geometry to provide differing flow configurations.  
         [0014]    [0014]FIG. 4 is a block diagram of the valve in one typical environment.  
     
    
     DESCRIPTION OF PREFERRED EMBODIMENTS  
       [0015]    Considering the drawings, wherein like reference numerals denote like parts throughout the various drawing figures, reference numeral  20  is directed to the valve according to the present invention.  
         [0016]    The heart of the valve  20  has ten components, shown in their sequence of assembly by a dotted line in FIGS. 1 and 2. FIGS. 3A and 3B show further variations of three of the ten components: the housing  1 ; insert  2 ; and disc gate  3 . These variations are illustrative and not exhaustive.  
         [0017]    Housing  1  is a hollow polyhedron having an open top  68  and circumscribing flange  70 . The hollowed portion includes its interior  50 . The housing preferably has a closed bottom wall  52 . Plural sides  64  are provided with plural portals  54 . In some variation (e.g. FIG. 1) some sides  66  have no portal. One portal  56  may receive a cylindrical “femleg” coupling  10  or other fluid transfer instrument, such as tubing, a syringe, etc. Coupling  10  has an exterior thread  58  at one end and an (optionally unthreaded) annulus  60  at another exterior end. Annulus  60  may be press fit into portal  56  or can be provided with threads in a threaded portal  56 . The coupling  10  is hollow with a cylindrical passage  62  which allows fluid to pass there through, into and out of the housing  1 . FIGS. 1, 2 and  3  show various contours of the housing  1  and various flow path possibilities in conjunction with differing insert  2  geometry and disc gate  3  geometry. In FIG. 3, housings having sides  64  with portals  54  illustrate  2  through  8  portals. Insert  2  is a polyhedron shaped substantially complemental to its housing  1 . Thus, if the housing has four portal bearing sides, so does the insert, typically. Insert  2  is made from ceramic.  
         [0018]    Insert  2  has a plurality of passageways  80  extending through its body, from a top  82  to sides  84 . As mentioned, it is preferred the passageways of the sides  84  match with the portals  54  and  56  to allow fluid flow. FIGS. 1 through 3 show various passageway patterns for the top  82  of the insert  2 . The top passageways coact with disc gate  3 .  
         [0019]    [0019]FIGS. 1 and 2 show the top  90  and side  92  of the disc  3 . Top  90  has two recesses  94 . These recesses coact with prongs  42  on drive stem  4  to rotate disc  3  to gate fluid between passageways  80  on top  82  of insert  2 . The bottom face  96  is depicted in FIG. 3 to illustrate variations in the geometry of a relief channel  98  formed on the bottom face  96 . Basically, channel  98  is either an elongate linear oval or a “kidney”-shaped curved oval. Linear ovals typically are radially deployed allowing fluid flow between a central passageway  80  and a peripheral passageway on the top  82 . Kidney-shaped, curved ovals typically allow fluid flow between the peripheral passageways  80  on the top  82 . These relief channels  98 , as a consequence determine which of the passageways  80  on the sides  84  and top  82  receive fluid since a respective one peripheral passageway  80  on the top  82  is in fluid communication with an adjacent corresponding side passageway  80  on its immediate side  84 . As mentioned, each side passageway registers with a portal  54  or  56  for fluid through passage.  
         [0020]    Drive stem  4  has a somewhat cylindrical body  44 . The prongs  42  are supported on an enlarged end  46  having a radially extending shelf  48  at the juncture with body  44 . The top of drive stem  4  is slotted, providing a key way  49  to be driven by a blade  51  carried on an external driver which meshes into key way  49 . The drive stem  4  is driven by a key way blade  51  carried by a shaft of motor shown in FIG. 4 which extends through a hollow of shaft  9  rotating the disc gate  3  feeding various passageways  80  and therefore portals  54 ,  56 . Shaft  9  has a necked-down, cylindrical upper end  53  The shelf  48  in conjunction with an enlarged lower end  55  of shaft  9  allows the serial stacking of a ball bearing  5 , bearing riser  6 , spring  7  and an upper bearing  8  as shown in FIGS. 1 and 2 with stem  4  next to bearing  5 , next to riser  6 , followed by spring  7  and bearing  8  and lastly shaft  9 .  
         [0021]    In a preferred use, FIG. 4 shows a shaft motor  22  rotating driving stem key way  49  with key  51  rotating stem  4  about arrow “A”. Valve  20  is coupled via femleg coupling  10  to a syringe  24  having a plunger  26  which linearly reciprocates along arrow “B” via plunger motor  30 .  
         [0022]    Disc  3  serves as a gate to insert  2  and is in tight placement there against by virtue of spring  7  and the close tolerance fit of the end  55  of shaft  9  within the flange  70  of housing  1  which is preferably threaded. Insert  2  is made of aluminum oxide (“alumina”). Preferably, it is substantially pure. Insert  2  is thus formed from ceramic. Disc  3  can also be made of ceramic, however, it can also be made of other materials, such as plastic, Teflon-filled amalgams, etc. Disc  3  could be a laminate with a ceramic on bottom surface  96  and in relief  98 . The housing can be aluminum, stainless steel, PEEK, etc.  
         [0023]    One consequence of the ceramic is that fittings (e.g. coupling  10 ) can be tightened down very tightly, preventing leaks. Heretofore, non-ceramic inserts were susceptible to distortion in the presence of high torqueing on fittings. This problem caused leaks which do not exist when practicing the present invention.  
         [0024]    Note that shaft  9  includes circumferential grooves  15  and that housing  1  has a notch  17 . The grooves  15  couple to the driver housing. Notch  17  diverts any weeping of fluid thereat. Weeping can be used to signal it is time to clean (in a solvent) the ceramic insert  2  and/or disc  3 , should it be made of ceramic.  
         [0025]    Moreover, having thus described the invention, it should be apparent that numerous structural modifications and adaptations may be resorted to without departing from the scope and fair meaning of the instant invention as set forth hereinabove and as described hereinbelow by the claims. For example, the features of this system accommodate the valve(s) with pumps and reservoirs, syringes per se, and in sampling and transferring metered amounts of fluids. Furthermore the valve allows replacement of a multiplicity of elements as shown in FIGS. 3A and B. This allows system reconfigurations and component repair from inventory, which is unknown in the prior art. Heretofore the inserts and discs required custom machining and fitting.