Patent Publication Number: US-2003233711-A1

Title: Washing machine water fill system

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS  
       [0001] Not applicable.  
       BACKGROUND—FIELD OF INVENTION  
       [0002] This invention relates to washing machines, specifically, to the water fill system.  
       BACKGROUND—DESCRIPTION OF PRIOR ART  
       [0003] The prior art is shown in FIG. 1. A washing machine has a mixing valve  20  to independently control the flow of hot and cold water from hot and cold water sources  12 . The mixing valve  20  is located within the washing machine housing  30 . Water is fed to the mixing valve by two hoses  14 . These hoses are shipped with the washing machine, and the hoses have female swivel connectors on each end. The mixing valve has two inlets  22  with male threads, so the hoses connect directly to it. The water source lines  12  usually have either a single throw valve  10  or two faucets to open or close both hot and cold water supplies. The single throw valve  10  or faucets usually have male threads, so the hoses  14  connect directly to them. If the single throw valve  10  or faucets do not have appropriate threads, appropriate connectors are obtained from a plumbing parts supplier to complete the installation of the washing machine.  
       [0004] The mixing valve  20  is composed of a plastic housing with two inlets  22  and an outlet  28 , and two electrically controlled plug elements  24  for preventing or allowing water to flow. Electrical control comes to contacts  26  via wires  34  from a controller  32 . For cost reasons, the water streams, after passing through the plugs  24 , are normally combined into a single stream inside the mixing valve  20  and then the stream flows through an outlet  28 . Water flows from the outlet  28  through a low pressure hose  36  which carries the water to the washing machine tub  38 .  
       [0005] This system has one major problem. The hoses  14  between the single throw valve  10  or faucets and the mixing valve inlets  22  are constantly under the full high pressure of the water source. Although the hoses  14  supplied with the washing machines are intended for this high pressure, the hoses  14  occasionally rupture. The rupture rate is very low, but the cost of the resulting flooding damage is often very high. Washing machine manufacturers could supply stronger hoses, but this would increase their cost. Washing machine owners could replace the hoses with stronger hoses available from many plumbing parts suppliers, but most owners do not do so. Owners of washing machines also could turn off the water at the source by shutting the single throw valve  10  or faucets, but most owners rarely do so.  
       [0006] U.S. Pat. Nos. 5,713,222, 5,560,231, 5,375,438, 4,809,524, 4,754,622, 3,566,906, 3,605,455, 2,871,871, 2,552,398, 2,523,801, and 2,498,179 all deal with water fill systems, but are concerned with water flow after the mixing valve. U.S. Pat. No. 3,020,741 relates to protection against backflow. None of these patents claim means of eliminating the hose rupture problem.  
       [0007] U.S. Pat. No. 5,425,255 claims a method of improving isolation between the electrical contacts of the mixing valve plug  26  and the washing machine water moisture. The intent of the patent is to improve reliability by reducing the chance of moisture induced corrosion of the electrical contacts. The disadvantage of the patent is that the improved isolation is accomplished by the addition of a physical barrier in the washing machine housing  30 , at added cost to the washing machine manufacturer.  
       SUMMARY  
       [0008] In accordance with the current invention, the mixing valve is moved from being located inside the washing machine to being attached directly to the water source. Only minor modifications are needed to the mixing valve. The outlet of the mixing valve and the electrical power to it can use the same connections and materials as in the prior art.  
       OBJECTS AND ADVANTAGES  
       [0009] Accordingly, several objects and advantages of this invention are:  
       [0010] (a) to eliminate hoses that sustain continuous high water pressure, thereby reducing washing machine manufacturing cost;  
       [0011] (b) to eliminate hoses that sustain continuous high water pressure and occasionally fail, often causing extensive and costly damage, thereby improving reliability;  
       [0012] (c) to use the same connections and materials on the washing machine side of the mixing valve as is currently used, thereby saving re-tooling costs;  
       [0013] (d) to have a system that, if electrical power is lost, places a closed water valve at the water source, thereby improving reliability; and  
       [0014] (e) to move the electrical contacts to the mixing valve far from the washing machine tub so that corrosion due to proximity to water moisture is reduced without any added cost to the washing machine manufacturer. 
     
    
    
     DRAWING FIGURES  
     [0015]FIG. 1 shows the prior art using a single throw valve to control both hot and cold water supplies.  
     [0016]FIG. 2 shows the improved water fill system using female threads on the mixing valve inlet and a three piece mixing valve.  
     [0017]FIG. 3 shows details of the female threads arrangement on the mixing valve inlet with swivel cross sectioned.  
     [0018]FIG. 4 shows the improved water fill system using male threads on the mixing valve inlet and a one piece mixing valve.  
     [0019]FIG. 5 shows the improved water fill system using female threads on the mixing valve inlet, a two piece mixing valve, and a Y-type outlet tube.  
    
    
     DESCRIPTION—FIGS.  2  AND  3 —PREFERRED EMBODIMENT  
     [0020] A preferred embodiment of the improved washing machine filling system is shown in FIGS. 2 and 3.  
     [0021] In FIG. 2, the mixing valve is composed of two separate valve elements  40 ,  41  each having its own inlet  42  from the water source, and a hose  46 . The outlet  44  of one valve  40  is connected to a second inlet  46  of the other valve  41  by a short connection hose  46 . Hose  46  can be made of the same material as prior art outlet hose  36 . Water flows from the second valve  41  through its outlet  44  via a second outlet hose  48  to the tub  38 . Connection hose  46  and outlet hose  48  are connected to the mixing valves in the same way as outlet hose  30  is connected to the mixing valve outlet  28  in the prior art. The mixing valves  40 ,  41  differ on the outlet side of the plugs  24  in that valve  40  has only an outlet  44  and valve  41  has both an outlet  44  and an additional inlet  46 . There is no requirement as to which valve  40 ,  41  carries hot water or cold water. Valve  40  could be replaced by a valve identical to valve  41 , as long as a means of closing off the unused inlet is employed. Many well known methods could be employed for this closure. Mixing valve elements  40 ,  41  are attached to and electrically controlled by wiring  50  and controller  32  as in the prior art. Outlet hose  48  and wiring  50  can be the same as outlet hose  36  and wiring  34  of the prior art, except for length.  
     [0022] Because the electrical contacts  26  to the mixing valve  40 ,  41  are now outside the washing machine housing  30 , the chance for degradation of the contacts due to proximity to the washing machine water moisture is reduced.  
     [0023] Re-tooling is needed to make the new mixing valve. Only the plastic housing of the prior art mixing valve  20  needs to be changed. The parts associated with the plugs  24  and electrical contacts  26  are unchanged.  
     [0024] The mixing valve inlets  42  may have male or female threads. In the prior art the inlets  22  use male threads. In the preferred embodiment of FIG. 2, the threading is female, as shown in more detail in FIG. 3. Swivel  42 A, shown cross sectioned, contains female threads needed to connect to the single throw valve  10  or faucets. A washer  45  is placed on the end of the shaft  43  to obtain a conventional water tight connection to the single throw valve  10  or faucets when the swivel  42 A is tightened. The female swivel  42 A, washer  45 , and shaft  43  are a well known arrangement found in many low cost products. This ensures that the preferred embodiment can be manufactured at low cost. By connecting the mixing valves directly to the single throw valve  10  or faucets, the prior art hoses  14 , are eliminated, saving cost. By eliminating hoses  14 , hose rupture is no longer possible, improving reliability.  
     [0025] The plugs  24  within the various mixing valves  20 ,  40 ,  41  are all operated electrically. The electrical signals involved are low dc or ac voltages, so placing the electrical connections external to the washing machine housing  30  does not pose a danger of electrical shock. In the absence of electrical power, the plugs  24  are in a closed position. Therefore, even if electrical power is lost, the high pressure water is terminated immediately at the outlet of the single throw valve  10  or faucets, adding to protection against major water damage.  
     [0026] A gasket  52  applied to the opening in the washing machine housing  30  through which the wires  50  and low pressure outlet hose  48  enter the washing machine housing  30 . This protects both wires  50  and hose  48  from chaffing.  
     [0027] Alternative Embodiments —FIGS. 4 and 5  
     [0028]FIGS. 4 and 5 show two alternative embodiments of this invention.  
     [0029] In FIG. 4, the structure of the prior art mixing valve  10  as a single unit is retained for the new mixing valve  60 . Female-to-female swivel connectors  64  obtainable from many plumbing parts suppliers connect the mixing valve  60  inlets  62  to the single throw valve  10  or faucets, which will require re-tooling the plastic. The spacing between the two inlets  62  needs to match that of the outlets of the single throw valve  10  or faucets. Matching spacing of the two inlets  62  to the outlets of the single throw valve  10  has some margin for manufacturing variations because the axis of the swivel  64  and the axis of the inlet  62  do not need to be perfectly aligned during the tightening. This approach requires less re-tooling than is needed in the preferred embodiment since the prior art male thread inlet  22  is retained for inlet  62  rather than the preferred embodiment FIG. 2 female inlet  42 . However, miss-matches in temperature coefficients and the effects of other mechanical movement may make maintenance of a good water tight seal a difficult engineering task. A second disadvantage of this embodiment is that, when faucets are used, the spacing of faucets is much less well controlled than on the single throw valve  10 . Additional plumbing connector parts may then be needed for installation. By using short pieces of high pressure hose in this arrangement, reliability compared to the prior art would be improved, but the arrangement is not as compact or as esthetically pleasing as the preferred embodiment. This arrangement is also expected to be more expensive than the preferred embodiment. Detailed analysis by those skilled in the art should be done to verify which approach should be used.  
     [0030] It will be obvious to the reader that instead of the male treads on the one piece mixing valve inlets  62  in FIG. 4, female threads as shown in the preferred embodiment in FIGS. 2 and 3 could be used.  
     [0031] It will also be obvious to the reader that in the preferred embodiment, swivels  42  could be replaced by male threaded inlets  62  and swivel valve connectors  64 . The arrangement of FIG. 3 is preferred over the alternate embodiment because the cost of the female threading arrangement  42  as an integral part of the mixing valve system is expected to be lower cost than the cost of female-to-female connectors  64 . Detailed analysis by those skilled in the art should be done to verify which approach should be used.  
     [0032] Another alternative embodiment is shown in FIG. 5. For an arrangement using two separate but identical valves  40 , the outlet  44  from each mixing valve goes to a Y-type outlet hose  66 . The arrangement of FIG. 2 is preferred over the arrangement of FIG. 5 because the cost of two different valves  40 ,  41  in FIG. 2, including both added tooling and added inventory control cost, is expected to be lower than the cost of the Y-type hose connection  50 . Detailed analysis by those skilled in the art should be done to verify which approach should be used.  
     [0033] Those skilled in the art will understand that any features incorporated in the hoses  14  or mixing valve  20  of the prior art which are not specifically described here can be applied directly to this invention. One example is the use of a washer with a screen filter in the hoses  14 . These can be used in place of the washer  45  or can be placed in the connectors  64 . Another example is that any backflow protection incorporated in mixing valve  20  can be incorporated in mixing valves  40 ,  41 ,  60  or in the Y-type outlet hose  66 .  
     [0034] Advantages  
     [0035] From the description above, a number of advantages of this improved washing machine filling system become evident:  
     [0036] (f) hoses that sustain continuous high water pressure have been eliminated, thereby reducing washing machine manufacturing cost;  
     [0037] (g) by eliminating hoses that sustain continuous high water pressure and occasionally fail, often causing extensive and costly damage, reliability is improved;  
     [0038] (h) by using the same connections and materials on the washing machine side of the mixing valve as is currently used, re-tooling costs are kept low;  
     [0039] (i) the new system is such that, if electrical power is lost, a closed water valve is placed directly on the water source, improving reliability; and  
     [0040] (j) by moving the electrical contacts between the washing machine and the mixing value outside the washing machine, the possibility of corrosion due to proximity to the water moisture in the washing machine is reduced, improving reliability.  
     [0041] Conculsions, Ramifications, and Scope  
     [0042] Accordingly, it is evident that, by eliminating hoses currently supplied with the washing machines, the invention reduces manufacturing costs of washing machines and eliminates a reliability problem that can be a major cost to owners of washing machines. Retooling costs for washing machine manufacturers can be limited to the plastic part of the mixing valve.