System to detect priming of a bulk dispense system for an appliance

Abstract

A bulk fluid dispensing system that can detect when priming has occurred is provided. The system can prime itself so as to remove e.g., air gaps that might affect the metering of a proper amount of a fluid such as laundry detergent or fabric softener into a wash chamber or wash bin of the appliance. A pressure sensor can be used to determine when such priming has occurred. Other features can be provided as well.

What is claimed is: 
     
         1 . A system for dispensing a fluid in an appliance, comprising:
 a tank for storing the fluid;   a pumping device for drawing fluid from the tank, the pumping device having an inlet and an outlet, wherein the inlet is connected to receive fluid from said tank;   a pressure sensor configured for providing one or more pressure measurements of fluid between said tank and said pumping device;   at least one processing device configured for
 activating said pumping device so as to draw fluid from said tank; 
 receiving pressure measurements of the fluid from said pressure sensor; and 
 determining when the pressure measurements of the fluid become substantially constant after said step of activating said pumping device. 
   
     
     
         2 . A system for dispensing a fluid in an appliance as in  claim 1 , wherein said pumping device comprises an aspirator that is fluidly connected with said tank and a water supply. 
     
     
         3 . A system for dispensing a fluid in an appliance as in  claim 1 , wherein said pumping device comprises a positive displacement pump. 
     
     
         4 . A system for dispensing a fluid in an appliance as in  claim 1 , further comprising:
 a fluid conduit connecting said tank and said pumping device;   wherein said pressure sensor is connected to said fluid conduit and is configured to measure the pressure of fluid flowing between said tank and said pumping device.   
     
     
         5 . A system for dispensing a fluid in an appliance as in  claim 1 , wherein said tank has a bottom, and wherein said pressure sensor is positioned near or below the bottom of said tank. 
     
     
         6 . A system for dispensing a fluid in an appliance as in  claim 1 , said appliance having a wash chamber or wash tub, and wherein the outlet of the pumping device is configured to provide the fluid to said wash chamber or wash bin of the appliance. 
     
     
         7 . A system for dispensing a fluid in an appliance as in  claim 4 , wherein said at least one processing device is further configured to meter the amount of fluid delivered into the wash chamber or wash tub of the appliance once the pressure measurements from said pressure sensor become constant. 
     
     
         8 . A system for dispensing a fluid in an appliance as in  claim 1 , wherein said at least one processing device is further configured for
 receiving one or more pressure measurements from said pressure sensor when fluid is not flowing through said pumping device;   ascertaining the amount of fluid in said tank when fluid is not flowing through said pumping device; and   providing a notification to a user of the appliance that is indicative of the amount of fluid remaining in said tank.   
     
     
         9 . A system for dispensing a fluid in an appliance as in  claim 1 , wherein the appliance is a washing machine. 
     
     
         10 . A method for dispensing a fluid in an appliance, comprising the steps of:
 providing a supply of the fluid for delivery in the appliance;   causing the fluid to flow along a path from the supply to a wash chamber of the appliance;   measuring the pressure of the fluid along the path during said step of causing; and,   determining when the pressure of the fluid become constant along the path during said step of causing.   
     
     
         11 . A method for dispensing a fluid in an appliance as in  claim 10 , further comprising the step of metering the fluid delivered to the wash chamber once the pressure of the fluid becomes constant as confirmed by said step of determining. 
     
     
         12 . A method for dispensing a fluid in an appliance as in  claim 11 , wherein said metering step comprises calculating the amount of time to operate one or more pumping devices after the pressure of the fluid becomes constant as confirmed by said step of determining. 
     
     
         13 . A method for dispensing a fluid in an appliance as in  claim 12 , further comprising the step of operating the one or more pumping devices for at least the amount of time provided by said step of calculating. 
     
     
         14 . A method for dispensing a fluid in an appliance as in  claim 10 , further comprising the steps of:
 determining the level of amount of fluid remaining in the supply by measuring the fluid pressure when fluid is not flowing from the tank.   
     
     
         15 . A method for dispensing a fluid in an appliance as in  claim 10 , wherein said causing step comprises drawing fluid from a position near the bottom of the tank using a pumping device. 
     
     
         16 . A method for dispensing a fluid in an appliance as in  claim 10 , wherein said fluid is a laundry detergent or fabric softener. 
     
     
         17 . A method for dispensing a fluid in an appliance as in  claim 10 , wherein the appliance is a washing machine.