Abstract:
An electrically operable valve assembly having an integral pressure regulator provides ease of installation and compact packaging for a water supply control system. The valve assembly is particularly useful for systems that control household water supplies to prevent flooding, but is also useful in other applications such as agricultural and industrial systems where water pressure determined water flow volume must be predicted accurately. The valve may also incorporate a flow meter having a positive flow characteristic permitting determination of very low flow rate flow and the valve may incorporate a manual control. All of the controls and features are integrable within a compact package that occupies essentially the same volume and piping space as a conventional electrically operable valve.

Description:
RELATED APPLICATIONS  
       [0001]    The present application is related to U.S. patent application Ser. No. __/______ entitled “METHOD AND SYSTEM FOR CONTROLLING A HOUSEHOLD WATER SUPPLY” filed concurrently with this application and also to U.S. patent application Ser. No. __/______ entitled “POSITIVE FLOW METER” also filed concurrently with this application. The specifications of both of the above-referenced applications are incorporated herein by reference. 
     
    
     
       BACKGROUND OF THE INVENTION  
         [0002]    1. Field of the Invention  
           [0003]    The present invention relates generally to liquid control valves, and more specifically, to an electrically operable valve assembly for controlling a water supply.  
           [0004]    2. Background of the Invention  
           [0005]    Water supply valves for household use are generally mechanical valves, although electrically operable sprinkler control valves are common. Electrically operable valves, if used on household water supplies are typically motor driven valves that use rotation to move a gate that shuts off water flow in the same manner as a mechanically operated valve.  
           [0006]    Pressure regulators are sometimes installed on the household water supply in areas where the pressure may exceed desirable operating levels for household appliances and other fixtures. Sprinkler systems also have pressure ratings that may be exceeded if the household water supply pressure rises too high due to external conditions at a city water distribution grid, for example.  
           [0007]    A pressure regulator requires in-line installation space and additional assembly time when used with a valve. Therefore, it would be desirable to provide an electrically operable valve and a pressure regulator that do not require additional assembly time and in-line space.  
         SUMMARY OF THE INVENTION  
         [0008]    The above objective of providing an electrically operable valve and a pressure regulator that do not require additional in-line space and assembly time is achieved in an electrically operable valve assembly having an integral pressure regulator. The valve and regulator are incorporated within one housing, and the pressure regulating mechanism may form part of the valve closure mechanism. A flow meter may also be integrated within the housing as well as a manual cutoff mechanism, providing multiple functions within one compact housing.  
           [0009]    The foregoing and other objectives, features, and advantages of the invention will be apparent from the following, more particular, description of the preferred embodiment of the invention, as illustrated in the accompanying drawings.  
       
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0010]    [0010]FIG. 1 is a mechanical drawing depicting a cross-section of an electrically operable valve in accordance with an embodiment of the invention.  
         [0011]    [0011]FIG. 2 is a mechanical drawing depicting a top view of an electrically operable valve in accordance with an embodiment of the invention.  
         [0012]    [0012]FIG. 3 is a mechanical drawing depicting a cross-section of an electrically operable valve in accordance with an alternative embodiment of the invention.  
         [0013]    [0013]FIG. 4 is a mechanical drawing depicting a cross-section of an electrically operable valve in accordance with another alternative embodiment of the invention.  
     
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS  
       [0014]    1. Electrically Operable Valve  
         [0015]    Referring now to the figures and in particular to FIG. 1, an electrically operable valve assembly  10  in accordance with an embodiment of the present invention is depicted. A water supply inlet  11  provides a connection to a water supply system such as a city water main connection. A household water supply outlet  12  provides connection to a household water supply system. In the depicted embodiment, electrically operable valve assembly  10  includes a backflow preventor, which prevents any backflow of water to the water supply. The backflow preventor comprises a piston  30  and spring  31  that prevent the flow of water when back water pressure moves piston  30  to compress spring  31 . Alternatively, as shown in balloon  40 , a ball  30 B may be used in place of piston  30 , with the ball mounted above a spring  31 A. The backflow preventor device is closely coupled to the operation of an integral flow meter, which will be described in further detail below.  
         [0016]    Control of electrically operable valve assembly  10  is provided by a piston-mounted gasket assembly  20  that shuts off the main water channel from water supply inlet  11  to household water supply outlet  12 . Gasket assembly  20  is slidably mounted on an outer piston  23  that surrounds an inner piston  22 . Outer piston  23  is mechanically coupled to a lower diaphram  16 . Electrically operable valve assembly is closed by water pressure on the lower side of lower diaphram  16  causing outer piston  23  to move gasket assembly  20  to force the gasket against seat  21 . The water pressure on the lower side of lower diaphram  16  is supplied by a channel  15  that receives flow when a piston  14  coupled to electrical solenoid  13  is in the raised position. Referring momentarily to FIG. 2, channel  15  receives flow from central aperture  51  which in turn receives flow from peripheral aperture  55  when piston  14  is raised (an o-ring or washer is provided at the end of piston  14  to provide a seal). Peripheral aperture  55  is coupled to water supply inlet  11  and thus provides a source of pressure higher than household water supply outlet  12 .  
         [0017]    Since the only path to the lower side of lower diaphram  16  is provided through channel  15 , when piston  14  is lowered, water pressure must be relieved through channel  15  to open electrically operable valve  10 . Piston  14  is hollow, and provides a connection from channel  15  (via central aperture  51  of FIG. 2) to a side port channel  24  that extends around the diaphram assemblies and connects to an exit channel  26  on the outlet side  12  of electrically operable valve  10 . Referring to FIG. 2, the path of channel  24  connects through channels  54  and  56  to channel  17  and venturi  18  of FIG. 1. Flow in the main channel of electrically operable valve  10  causes a reduced pressure at venturi  18 , pulling water through the above-described path from the top side of lower diaphram  16  as the valve closes. A stop ball  53  disposed within channel  54  prevents backflow through this path.  
         [0018]    Solenoid  13  may be a latching-type solenoid, permitting a momentary pulse to operate electrically operable valve assembly  10 . A latching solenoid is preferred for extending solenoid life and for reducing power consumption and noise, but a standard solenoid may be preferred if it is desirable to cut-off water flow when electrical supply to the assembly fails.  
         [0019]    2. Pressure Regulator  
         [0020]    Upper diaphram  25  provides a pressure regulator integrated within electrically operable valve assembly  10 . A channel  17  connects to a venturi  18  that couples the household water outlet side  12  of electrically operable valve assembly  10  to the lower side of upper diaphram  25 . The pressure supplied through channel  17  to upper diaphram  25  acts against spring  27  that is manually adjustable via turnscrew  28 . When the outlet pressure exceeds a level as set by turnscrew  28  adjustment, upper diaphram  25  lifts inner piston  22 , raising gasket assembly  20 , restricting the flow through the main channel of electrically operable valve assembly  10 . Thus, a pressure feedback mechanism is established that regulates the pressure at outlet  12 .  
         [0021]    3. Flow Meter  
         [0022]    A flow meter may be implemented within electrically operable valve assembly  10  by a sensor  35  mounted near bypass channel  32  inlet. A ball  34  is mounted within bypass channel  32  and may be made of a magnetized material or ferromagnetic material for use with a hall effect sensor. Sensor  35  may be a hall effect sensor, inductive sensor or other suitable sensor for detecting the proximity of ball  34 . The output indication from sensor  35  may be a continuous analog reading of the position of ball  34 , or a binary flow/no-flow indication.  
         [0023]    The flow meter implemented by ball  34  and sensor  35  is a positive flow meter in that any flow through valve assembly  10  will move ball  34  away from sensor  35 , providing measurement of flows much lower than flow rates detectable with conventional flow meters for household water supply applications, which typically cannot detect flows below 0.5 gallons per minute. The positive flow meter permits detection of low volume water leaks that may cause damage to a structure without registering a flow at a flow meter detection system. Since any flow through valve assembly  10  requires a pressure drop between water supply inlet  11  and household water supply outlet  12 , ball  34  will move away from sensor  35  as flow through bypass channel  32 . Spring  33  has a very low spring constant and very little force on ball  34  is required to compress spring  33 . When no flow (or back flow begins to occur), ball  34  will be forced by spring  33  against seat  36 , effectively closing bypass channel  32  to prevent backflow leakage. Setscrew  37  permits adjustment of the cross-section of bypass channel  32 , providing a means for adjusting the sensitivity of the flow meter at the factory or after installation. As the channel cross-section decreases, the amount of force compressing spring  33  for a given flow rate will increase, thus increasing the sensitivity of the flow meter.  
         [0024]    Spring  31  is designed so that gasket assembly  30  will not open the main valve channel until the sensor  35  detects positive flow and therefore any flow through electrically operable valve assembly  10  will result in an indication from sensor  35 . The above operation is accomplished by making the spring constant of spring  31  such that ball  34  will travel past sensor  35  before spring  31  is compressed to open the main valve channel.  
         [0025]    4. Alternative Electrically Operable Valve and Flow Meter 1  
         [0026]    Referring now to FIG. 3, an electrically operable valve and flow meter in accordance with an alternative embodiment of the invention is depicted. In this embodiment, the pressure regulator is removed from the embodiment depicted in FIGS. 1 and 2, simplifying the structure of the assembly. In the depiction, like reference numbers are used to indicate the corresponding components, the operation of which is described above for the embodiment of FIGS. 1 and 2. Therefore, only differences between the assemblies will be described.  
         [0027]    Piston  23 A is a single sleeve piston operating in similar fashion to outer piston  23  of FIG. 1. Piston  23 A does not have to be hollow, as inner piston  22  of FIG. 1 was provided to implement pressure regulation and is therefore not needed in the present embodiment. Piston  23 A is slidably coupled to gasket assembly  30 A, which is operated by diaphram  16  or backpressure from water supply outlet  12 , eliminating the need for the separate gasket assemblies  30  and  20  of FIG. 1. The sliding mount of gasket assembly  30 A in conjunction with spring  31  provides closure of the main channel at the onset of flow until ball  34  has seated against seat  36 , providing proper operation of the flow meter within the bypass channel. However, since forward pressure can be applied through channel  32  when the valve is closed (channel  32  in the embodiment of FIG. 1 is effectively closed by gasket assembly  20  when the valve is closed), a second seat  36 B is provided for ball  34  in the reverse flow direction, preventing leakage through the flow meter channel  32  when the valve is closed. The bottom of seat  36 B is provided by a threaded insert  43  in the depicted embodiment. In order for ball  34  to move when a forward flow is generated through the valve assembly, water must flow channel  32 . Forward flow is provided by a channel passing through threaded insert  43 . Balloon detail  42  depicts the above-described channel  38  that is cross-drilled through threaded insert  43  to connect with the hole that is drilled to retain spring  33 . When the valve is closed, water can flow through channel  38  from the center of spring  33 , until ball  34  seats at bottom seat  36 B.  
         [0028]    5. Alternative Electrically Operable Valve 2  
         [0029]    Referring now to FIG. 4, an electrically operable valve  70 , in accordance with an alternative embodiment of the invention is depicted. The alternative embodiment incorporates a backflow prevention device within valve  70  and a manual cut-off shaft  79  that operates the piston  63  used for electrically actuating valve  70 . As in the first embodiment, piston  63  is driven by a spring  78  that provides an initial compressive force against piston  63  providing a pressure reduction via the operation of piston  63 . The compressive force is overcome by a pressure drop between a water supply inlet  71  and a household water supply outlet  72 . A bypass channel  76  is provided from water supply inlet  71  to household water supply outlet  72  providing equalization of pressure from water supply inlet  71  to household water supply outlet, when an o-ring  62  mounted on a shaft of a solenoid  60  is in a retracted position.  
         [0030]    When solenoid  60  is activated, o-ring  62  seats against the housing of valve  70 , closing bypass channel  76  and permitting a pressure drop to develop across the main valve channel. The pressure drop moves piston  63  upward, compressing spring  78 , providing a pressure-regulated flow through valve  70 . As described above for the preferred embodiment, solenoid  60  may be a momentary latching type solenoid or a standard solenoid.  
         [0031]    A second piston  73  provides a backflow prevention device and may alternatively be used for pressure regulation or may be used in combination with piston  63  and spring  78  to provide pressure regulation. Holes  74  through the housing cylinder containing piston  73  permit water to flow from the outside channel to piston  73 . Pressure in the forward direction of flow causes piston  73  to move upward, compressing spring  75  and moving piston so that channels  69  align with holes  74 , permitting water to flow through the central void of piston  73  through to household water supply outlet  72 . When flow reverses through valve  70 , piston  73  moves downward, decompressing spring  75  and seating o-rings above and below holes  74 , shutting off backflow through valve  70 .  
         [0032]    6. Alternative Flow Meter 2  
         [0033]    A flow meter is provided in the alternative embodiment of FIG. 4 by a sensor  66  integrated at the bottom of the valve housing. A disc or button  65  may be made of a magnetized material or ferromagnetic material and sensed by proximity to sensor  66 . When flow from water supply inlet  71  to household water supply outlet  72  occurs, piston  73  will move upward, retracting disc or button  65  from sensor  66 , providing an indication of flow through valve  70 . As described above for the first embodiment, output from sensor  66  may be a continuous indication of the position of disc or button  65  providing an indication of flow level or a flow/no-flow indication may be provided by sensor  66 .  
         [0034]    The embodiments of the invention described above disclose an electrically operable valve with pressure regulation, backflow prevention and a flow meter incorporated within one housing and using common mechanisms between the valve and pressure regulator. Both embodiments provide a flow meter capable of registering very low flow rates, so that household leak detection may be accomplished for very low flow rate leaks. The valve is suitable for use within the system and method described in the above-incorporated patent application “METHOD AND SYSTEM FOR CONTROLLING A HOUSEHOLD WATER SUPPLY”, wherein the valve will provide a compact solution having very high sensitivity to water supply system leaks.  
         [0035]    While the invention has been particularly shown and described with reference to the preferred embodiments thereof, it will be understood by those skilled in the art that the foregoing and other changes in form, and details may be made therein without departing from the spirit and scope of the invention.