Abstract:
The present invention provides a multi-element filtering system assuring serial filtration of a liquid through multiple filter cartridges while enabling flushing without requiring removal of the filter cartridges. Both conventional and reverse osmosis filtration is performed, sequentially, within the system. After filtration, the water is subjected to ultraviolet irradiation for purification. The filter cartridges are held within a canister which is pressed against the cap and constrained against rotation with the cap. The canister is divided into chambers, and has passages in its floor arranged to enable serial transfer of liquid from one chamber to the next. Flushing employs liquid introduced under normal pressure. Passages leading to the flush liquid outlet enable flushing to proceed when the flush liquid outlet is opened. At other times, filtered liquid will pass through passages leading to the filtered liquid outlet. Liquid is circulated to assure filtration even when flushing, so that contamination of filtered liquid is precluded.

Description:
CROSS REFERENCE TO RELATED APPLICATIONS 
     This application is a continuation-in-part of our U.S. patent application Ser. No. 09/788,533, filed on Feb. 21, 2001, entitled “MULTI-ELEMENT Reverse Osmosis, Liquid Filter System with Flushing and Filtering Circuits”, now U.S. Pat. No. 6,423,223; which is related to our issued U.S. Pat. No. 6,027,647, with a patent date of Feb. 22, 2000 entitled MULTI-ELEMENT LIQUID FILTER SYSTEM WITH FLUSHING AND FILTERING CIRCUITS; and is a Continuation-In-Part of our U.S. patent application No., 09/653,414, filed on Aug. 31, 2000, now abandoned. 
    
    
     BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates to water filters, and more particularly to a filter housing which accepts multiple, replaceable, reverse osmosis and carbon filter elements within a single housing. The filter elements are disposed in a serial arrangement for filtering purposes. Ultra-violet rays from a central core provide further bacterial purification of filtered water. The housing accommodates flushing without requiring removal OF the filter elements. 
     2. Description of the Prior Art 
     In light of many contaminants which may become entrained in water supplied by domestic plumbing systems, it is desirable to filter the water prior to employing the same for human consumption. Many filters are commercial products featuring filter cartridges which are readily installed and serviced by residential occupants who may lack specialized skills as a plumber. These filters conventionally comprise housings which enclose one or more filtering elements. Consequently, separate replaceable filtering elements are readily available from commercial sources. 
     A filter seen in U.S. Pat. No. 3,780,869, issued to Zaharias Krongos on Dec. 25, 1973, has a housing formed in two threadably mating parts, which housing encloses plural replaceable filter elements. The filter of Krongos lacks the flushing circuitry, reverse osmosis filtering, serial filtration circuitry, UV irradiation, and inlet and outlet arrangement of the present invention. 
     U.S. Pat. No. 30,366, issued to M. W. Warne on Oct. 9, 1860, shows a vessel having plural compartments, each containing filtration material and connected in series. The device of Warne lacks the reverse osmosis filtration, UV irradiation, flushing circuitry, inlet and outlet arrangement of the present invention, readily replaceable filter cartridges capable of holding their form without supporting, surrounding walls, and adjustable compression of such filter cartridges, all being features of the present invention. 
     U.S. Pat. No. 136,364, issued to Walter M. Conger on Mar. 4, 1873, illustrates a filter having filter elements disposed in series and also flushing circuitry. However, the device of Conger lacks the threaded, separable, two part housing of the present invention, reverse osmosis filtration, UV irradiation, flushing circuitry contained within a part of the housing, adjustable compression of filter cartridge elements, and the inlet and outlet arrangement, and internal flow scheme of the present invention. 
     None of the above inventions and patents, taken either singly or in combination, is seen to describe the instant invention as claimed. 
     SUMMARY OF THE INVENTION 
     The present invention provides a readily installed and serviceable filter apparatus which employs readily available filter cartridges and which further enables ready flushing. The novel filter apparatus includes a two part housing which can be opened to expose the plural filter cartridges without interrupting liquid connections. 
     The filter apparatus accepts a plurality of carbon and reverse osmosis filter cartridges. Internal liquid flow circuitry passes water in a serial routing through the several cartridges. This ability may be exploited to subject all water to filters designed to trap different contaminants. An ultraviolet source at the core of the filter housing provides irradiation for additional purification of the filtered water. The filter can be flushed automatically or with minimal difficulty, in particular requiring neither removal of the filter cartridges nor disassembly from the domestic plumbing system. The filter is configured to assure that water employed for flushing will not be discharged in common with filtered water. 
     Accordingly, it is a principal object of the invention to provide a water filter readily connectable to a domestic plumbing system. 
     It is another object of the invention to provide a water filter which accepts plural filter elements. 
     It is a further object of the invention that the filter employ commercially available filter cartridges. 
     Still another object of the invention is to enable flushing without requiring removal of filter elements. 
     An additional object of the invention is to prevent water employed to flush the filter from being discharged in common with filtered water. 
     It is again an object of the invention to provide a filter housing which opens to expose filter elements without requiring disassembly from the domestic plumbing system. 
     Yet another object of the invention is to enable compression of the housing to secure filter cartridges. 
     Still another object of the invention is to provide serial and parallel flow through multiple filter cartridges. 
     Another object of the invention is to provide filtration by reverse osmosis through at least one filter cartridge. 
     An additional object of the invention is to provide UV irradiation of the water being filtered. 
     Another object of the invention is to provide improved elements and arrangement thereof in an apparatus for the purposes described which is inexpensive, dependable and fully effective in accomplishing its intended purposes. 
     These and other objects of the present invention will become readily apparent upon further review of the following specification and drawings. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     Various other objects, features, and attendant advantages of the present invention will become more fully appreciated as the same becomes better understood when considered in conjunction with the accompanying drawings, in which like reference characters designate the same or similar parts throughout the several views, and wherein: 
     FIG. 1 is an exploded, perspective view of the invention. 
     FIG. 2 is an exaggerated, diagrammatic representation of fluid circuitry of liquid being filtered. 
     FIG. 3 is a modified plan view of the canister and porting block of the invention showing filtration and flushing passages. 
     FIG. 4 is a partial cross sectional view of the invention. 
     FIG. 5 is a partial cross sectional view showing the UV purification chamber in accordance with the present invention. 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     Referring now to FIG. 1 of the drawings, a novel multi-element filter system is shown to comprising the filter housing  10 , porting block  90 , and a tank  120 . Electrical feeds  16  supply power to electrical connectors  18  located at the center of the lower surface  42  of cap  12 . A canister  20  is divided into six separate chambers, hereinafter collectively referred to as chambers  22 , and individually referred to as chambers  22 A, B, C, D, E, and F, separated by six internal walls  24 . At the juncture of walls  24  is a central tube  26 . 
     Each chamber  22  contains one filter, hereinafter collectively referred to as filter cartridges  28 . Each of chambers  22 A,  22 B,  22 D and  22 E contain a carbon (charcoal) filter cartridge  28 C 1 - 28 C 4 . Each of chambers  22 C and  22 F contain reverse osmosis filters  28 R 1  and  28 R 2 . The filter cartridges  28  may be annular, open at the top and at the bottom, and are conventional, commercially available products. Each of the two types of filter cartridges (i.e., carbon and reverse osmosis) may differ in their filtration characteristics despite similar dimensions and configuration. 
     Cannister  20  has a bottom wall  30  and peripheral wall  32  in fluid connection with porting block  90 , and an open top  34  within an upper surface  36 . Bottom wall  30  and wall  32  are continuous so as to retain liquid within canister  20 . Recess  38  in upper surface  36  of canister  20  and circumferential groove  40  in the lower surface  42  of cap  12  are provided to receive gasket  45 . A tab (not shown) on the lower perimeter of gasket  45  fits into a slot (not shown) in recess  38  to ensure proper gasket alignment. Filter cartridges  28  are secured in place by a plurality of filter cartridge retainers  29  located in the lower surface  42  of cap  12  and bottom wall  30  of canister  20 . 
     Position of canister  20  relative to cap  12  is critical to alignment of filter cartridges  28  and filter cartridge retainers  29 . Consequently, alignment pin  44  in lower surface  42  of cap  12  fits into alignment aperture  46  in upper surface  36  of canister  20 . Cap  12  and canister  20  are joined by bolts (not shown), fitting through apertures (not shown) in the cap  12  and threaded into nuts (not shown) molded into upper surface  36  of canister  20 . 
     Liquid flow through filter housing  10  is shown in simplified, diagrammatic manner in FIG.  2  and in plan view in FIG.  3 . It will be recalled from FIG. 1 that chambers  22  are separated from one another by walls  24 . Unfiltered water, as shown by arrow  54 , obtained from the domestic water supply passes through an input pipe or conduit  50 , through check valve  55  to then transit to inflow ports  505   a  and  505   b  and enters chambers  22 A and  22 D, respectively, from bottom wall  30 . A sensor channel  501  is in fluid connection with inflow channel  500  to receive and test the initial contaminants of the domestic water supply by a sensor  502 . 
     Porting block  90  houses all inlet and discharge means by way of pipes or conduits  50 ,  70  and  80 . The porting block  90  also houses all valves, i.e., check valves  55  and  85 , and solenoid  7 . The pipes and conduits all lead to input and output channels which in turn are in fluid communication with the bottom of the  16  canister  20  to thereby enter the filtration, flushing, and purification circuits. 
     Water flows in through inflow channel  500  to input ports  505   a  and  505   b  into chambers  22 A and  22 D. As chambers  22 A and  22 D fill, pressure urges water through the filtering elements  28 C 1  and  28 C 3  into he open center of the respective cartridges. Filtered water from filtering element  28 C 1  and  28 C 3  then flows through channels  520  and  525 , respectively. Filtered water flowing through channel  520  then exits through exit port  521  into chamber  22 E. Simultaneously, filtered water flowing through channel  525  exits through exit port  526  into chamber  22 B. 
     As chambers  22 B and  22 E fill, pressure urges water through filtering elements  28 C 2  and  28 C 4  then flows through channels  530  and  535 , respectively. Filtered water from chamber  22 E is then channeled into the base of reverse osmosis filter  28 R 2  by way of channel  530 . Simultaneously, filtered water from chamber  22 B is then channeled into the base of reverse osmosis filter  28 R 1  by way of channel  535 . After reverse osmosis filtration, the filtered water from chamber  22 F is channeled onto channel  540  by way of input port  541 . Likewise, filtered water from chamber  22 C is channeled into channel  545  by way of input port  546 . 
     Channels  540  and  545  provide the path for the filtered water to enter into the last phase of purification, the UV circuit. Central tube  26  houses the UV irradiation means, i.e., the UV assembly  65 , as described in detail herein below. FIG. 4 is a cross sectional view along axis X (shown in phantom on FIG. 3) of chambers  22 A and  22 F. The UV assembly  65  has an ultra-violet (UV) source  69 , which may be a commercially available UV emitting light tube, connected to electrical connector  18 . 
     The UV assembly  65  is comprised of an ultraviolet light source  69  which is surrounded by a UV transmissive wall  100  which seals the UV source  69  from the waterflow. UV radiation emitted by UV source  69  passes through the UV transmissive wall  100  comprised of a quartz material. Exterior to the quartz wall  100  is a second wall  105  comprised of a non-UV transmissive material. Wall  105  is preferably comprised of non-UV transmissive materials such as stainless steel, a sufficiently doped material, or the like, however other suitable materials may be used. Exposing the filtered water to ultraviolet rays provides additional purification to any unfiltered bacteria remaining after the carbon and reverse osmosis filtration. 
     In the interest of prolonging the exposure of the water to the UV rays, a spiral  110  may be placed between the quartz wall  100  and the stainless steel wall  105 . Spiral  110  may be made of any suitable material that is resistant to ultraviolet radiation. Herein, the path that the water travels is increased, thus providing additional, bacterial purification of water passing through the filter device  10 . 
     As can be seen in FIG. 4, the reverse osmosis chamber  22 F contains reverse osmosis filter  28 R 2 , which is contained within a cylindrical sleeve  28 S 1  having external filter elements  28 Re surrounding the core of the filter  28 R 2 . Herein, the water traverses the interior space between the sleeve  28 S 1  and the core of the filter  28 R 2  for reverse osmosis filtration to then exit out of an exit port  28 P. After exiting through exit port  28 P, the filtered water then travels through channel  545  for entrance into the purification circuit. 
     FIG. 5 illustrates a cross sectional view showing the UV purification circuit located within central tube  26 . In accordance with industry standards, the water being treated by UV rays must be within one inch of the UV source. As depicted in FIG. 5, the variable D denotes the distance between the tube of the UV source  69  and the stainless steel wall  105 . With phantom dimension lines, it is shown that D&lt;1 inch. 
     Also shown in FIG. 5, after the filtered water enters the UV circuit via channel  545  into the UV purification channel  103  to begin the spiraling upwards alongside source  69 . The spiraling provides the water with a greater distance to travel during the purification by the UV rays, thus enhancing the purification step. Gasket  45  (as shown in FIG. 1) seals the top of central tube against lower surface  42  of cap  12  providing a fluid seal for each of the chambers, and especially the central tube  26 . 
     The UV treated water then exits out of an aperture  106  located within wall  105  to then travel along UV outflow channel  107  located between wall  105  and central tube  26 . With the water flow directions depicted by arrows, it is shown that purified water then exits through port  88 , along channel  86 , through output port  82  wherein the polished water is carried out via output pipe or conduit  80 . Arrow  84  indicated the final product, filtered, purified water. 
     Better shown in FIG. 4, the filtered, purified final water product, indicated by arrow  84 , is then fed into a storage tank  120 . The tank  120  may be pressurized. Tank  120  has a final output means, shown diagrammatically as tap  125 . 
     Filter  10  has four, independent flushing zones for removing contaminants from the system. A flushing zone is associated with each of the chambers containing charcoal filters, i.e., chambers  22 A,  22 B,  22 D and  22 E, respectively. A flushing pipe or conduit  70  is in fluid communication with a check valve  71 , which is connected to a solenoid device  7  which periodically provides back-flushing of the chambers  22 A,  22 B,  22 D and  22 E. 
     The solenoid device  7  is in turn controlled by a suitable control device (not shown). The control device may be a time-clock, a manual switch, or any other device enabling manual or automatic operation of the solenoids. The solenoids of the solenoid device  7  may be in a normally closed state and are energized to an open state. However, it can be appreciated by those of skill in the art that the converse state can alternatively be employed. 
     The flushing conduit  70  has a main output port  72  for channeling water from flush channel  75 . Flush channel  75  has flushing ports  76   a-d,  each associated with a flush zone as mentioned above. Accordingly, flush port  76   a  communicates with chamber  22 D, flush port  76   b  communicates with chamber  22 A, flush port  76   c  communicates with chamber  22 E and flush port  76   d  communicates with chamber  22 B. The flush circuit is actuated intermittently by solenoid device  7  to prevent contaminants from backing up throughout the filter  10  and water supply lines. Each flushing zone is ultimately connected to the flushing conduit  70  arranged to discharge flushing water to a suitable drain, (not shown) or other facility for disposal. 
     The present invention is susceptible to variations and modifications which may be introduced without departing from the inventive concept. Several examples of modifications will be set forth. Direction of flow of water is indicated by arrows. It should be noted that for simplification of the figures, the positioning of external connections in all drawings are illustrative and do not indicate exact alignments. The filter system  10  may be provided with any number of chambers  22  and appropriate fluid circuitry to accommodate any number of filter cartridges  28 . Bolts and nuts (not shown) joining cap  12  and canister  20  could be replaced by latching arms (not shown) or other fastening elements which could serve in their place. 
     It is to be understood that the present invention is not limited to the embodiments described above, but encompasses any and all embodiments within the scope of the following claims.