Abstract:
A water spout end device for producing laminar flow of the water emitted therefrom comprising a generally cylindrical housing containing a cylindrical plastic component formed with a plurality of annular passages divided by annular spoke-like walls and characterized in that the plastic component is molded from ingredients including an anti-microbial agent.

Description:
[0001]    This application is related to provisional patent application Ser. No. 60/249,372 filed Nov. 17, 2000. 
     
    
     
       FIELD OF THE INVENTION  
         [0002]    This invention relates to spout end devices. More specifically, this invention relates to laminar flow-type spout end devices having anti-microbial properties.  
         BACKGROUND OF THE INVENTION  
         [0003]    A common problem in hospitals, well known to the people responsible for infectious disease control, is the proliferation of disease-causing bacteria. Bathroom faucets are potential sites for bacterial colonization in the hospital environment because of the presence of moisture and their proximity to patients with infectious diseases.  
           [0004]    The part of the faucet most likely to harbor dangerous microbes is the spout end device because of its relatively large wetted surface area and its exposure to air and location closest to the point of use. Because of high risk of contamination by the ambient air, spout end devices of the aerator type with vast exposed surfaces are shunned in favor of laminar flow devices with less air-exposed surfaces. However, even after flow is stopped, a few drops of water invariably remain on its laminar-forming and other surfaces, susceptible to contamination by the ambient air.  
           [0005]    Recognition of this potential health hazard has led to the establishment of procedures in hospitals designed to sterilize the water system using high temperature water or extra doses of chlorination. However, at best, these procedures are carried out only infrequently.  
         SUMMARY OF THE INVENTION  
         [0006]    The invention is a laminar-flow end device for a water spout comprising a generally cylindrical plastic component through which water passes. The component is characterized in that the plastic is molded from ingredients including a thermoplastic resin and an anti-microbial agent. The invention thus provides for continuous retardation of bacterial growth in the spout end device. 
       
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0007]    Further objects and features of the invention will be clear to those skilled in the art from a review of the following specification and drawings, all of which present a non-limiting form of the invention. In the drawings:  
         [0008]    [0008]FIG. 1 is a side elevational view of an assembly embodying the invention, depicted in semi-lateral cross section; and  
         [0009]    [0009]FIG. 2 is also a side elevational view of an assembly disposed in a discharge orifice, also in semi-lateral section. 
     
    
     DESCRIPTION OF THE PREFERRED EMBODIMENT  
       [0010]    A laminar flow device is shown in an assembly in FIG. 1 and the assembly is generally designated  1 . It is disposed in a discharge housing  2  as is shown in FIG. 2. The discharge housing is connectable with the discharge end of a sanitary fitting (not shown).  
         [0011]    The assembly  1  (FIG. 1) comprises essentially three elements: a laminar flow device  3 , including a perforated plate  20  having a depending skirt  20   a  which blocks lateral entrance of air into the laminar flow device  3 , a flow-through volume controller  4  and a filter attachment  5 . The flow direction is designated by the arrow Pf 1 .  
         [0012]    The laminar flow device  3  with its annular passages  22  and their radial spoke-like walls  24  serves to organize the water into a laminar stream. It may be a modified form of the type shown and disclosed earlier in U.S. Pat. Nos. 5,495,985 and 5,769,326 which issued Mar. 5, 1996 and Jun. 23, 1998 respectively to Dieter Wildfang GmbH. The teachings of both of these patents are incorporated herein by reference.  
         [0013]    The flow-through volume controller element  4  serves as a largely water-pressure-independent limitation of flow-through performance. The attachment filter  5  lastly serves to keep solid particles accompanying the water away from the flow-through volume controller and the laminar flow device to ensure that they function properly and are not impaired.  
         [0014]    Depending on the application, various combinations of elements are provided. As an example, flow-through volume controllers  4  having various flow-through rates can be selectively used. There is also the option of using the laminar flow device  3  with a directly placed attachment filter  5  if no flow-through volume controller  4  is needed.  
         [0015]    To be able to attach mounting parts  3 ,  4 ,  5  optionally with each other, they themselves have snap-type connectors  6  that adapt in each case to each other (FIG. 1). Such connectors  6  are found on the laminar flow device  3  on its in-flow side end, on the flow-through volume controller  4  at both ends, and on the attachment filter  5  on its out-flow side end. The connectors  6  are described in detail in the aforementioned U.S. Pat. No. 5,769,326 and are not part of this invention.  
         [0016]    Turning to the present invention, anti-microbial compounds exist in various forms, some employing inorganic ingredients such as silver, zinc oxide and titanium dioxide; others consisting of organic compounds such as chlorinated phenols. The common characteristic of these compounds when mixed into the plastic resin is that they create a surface condition on the finished plastic parts that retards the growth of bacteria.  
         [0017]    Because spout end devices of most faucets are removable, anti-microbial spout end devices or components can be retrofitted into existing faucets, thereby supplementing the normal infectious disease control procedures in hospitals, for instance, and assisting in the prevention of disease.  
         [0018]    In the process of making the component of the invention, the plastic selected, in powder form, is mixed with a suitable quantity of powder of the anti-microbial agent. Preferably, the proportions are such that the portion of the mixture which is the anti-microbial agent is no more than 5-10% of the total mixture. A larger portion may adversely affect the stability of the mixture.  
         [0019]    The mixing should be sufficient to distribute the two powders intimately. The mixture is injected into a closed injection molding press. After setting, the mold is opened and the product ejected. Products made in accordance with the invention have the anti-microbial characteristics desired.  
         [0020]    The anti-microbial agent preferred in the practice of the invention is the inorganic type. Specifically, an agent containing silver and zinc and a carrier of alumino-silicate is preferred and is available as “Agion” from Agion Technologies of Wakefield, Mass.  
         [0021]    An organic anti-microbial agent may be a chlorinated phenol available under the trademark “Microban” from Microban Products Company of Charlotte N.C.  
         [0022]    Preferably, the thermoplastic resin used with the agent in the practice of the invention is an acetal, such as “Delrin” or “Celcon”. Under the invention the mixture is used in the molding of parts  3 ,  4  and  5 .  
         [0023]    Variations in the invention are possible. Thus, while the invention has been shown in only one embodiment, it is not so limited but is of a scope defined by the following claim language which may be broadened by an extension of the right to exclude others from making, using or selling the invention as is appropriate under the doctrine of equivalents.