Water filter monitoring and indicating system

Abstract

A method and apparatus for determining when a replaceable filter for a refrigerator needs replacing based on the volume of water passing through the water filter as determined by the product of the time that water has passed through the filter and the flow rate of an accessory being supplied the filtered water.

1 . in a refrigerator comprising an ice maker and a water dispenser, a water supply system for delivering filtered water from a water source to the ice maker and water dispenser, the water supply system comprising: 
 a replaceable water filter having an inlet for receiving water and an outlet for outputting water such that water passing through the water filter from the inlet to the outlet is filtered;    a water source conduit for connecting the water source to the filter inlet to supply the water filter with water;    a filtered-water conduit for connecting the filter outlet to the ice maker and the water dispenser to supply the ice maker and water dispenser with filtered water; and    a filter status unit for determining the status of the filter based on the filtered water demanded by the ice maker and water dispenser and comprising a water volume meter for determining the volume of filtered water outputted by the water filter for each demand of water, a filtered-water volume summing device for maintaining an accumulated filtered-water volume based on the filtered-water volume determined by the filtered-water volume meter for each demand, and an indicator for signaling when the accumulated filtered-water volume reaches a threshold value indicative of the need to replace the water filter.    
     
     
         2 . The water supply system according to  claim 1  and further comprising a valve fluidly connected to the filtered-water conduit for controlling the flow of filtered water through the filtered-water conduit from the filter to one of the ice maker and water dispenser.  
     
     
         3 . The water supply system according to  claim 2  and further comprising a second valve fluidly connected to the filtered-water conduit for controlling the flow of filtered water through the filtered-water conduit from the filter to the other of the ice maker and water dispenser.  
     
     
         4 . The water supply system according to  claim 3  wherein the filtered-water conduit comprises a first branch for connecting to the ice maker and a second branch for connecting to the water dispenser, and the valve is located in the first branch and the second valve is located in the second branch.  
     
     
         5 . The water supply system according to  claim 1  wherein the water volume meter comprises a timer for determining the duration of each demand for water by either the ice maker or water dispenser and a data processor for calculating the filtered-water volume for each demand based on the duration of each demand.  
     
     
         6 . The water supply system according to  claim 5  wherein the data processor comprises a memory in which is stored a flow rate for at least one of the ice maker and water dispenser and the water volume for each demand is determined by the data processor calculating the product of the duration and the flow rate.  
     
     
         7 . The water supply system according to  claim 6  wherein the memory of the data processor stores a flow rate for each of the ice maker and the water dispenser and the data processor selects the flow rate corresponding to which of the ice maker and water dispenser is demanding filtered water when calculating the filtered-water volume.  
     
     
         8 . The water supply system according to  claim 7  and further comprising a valve fluidly connected to the filtered-water conduit for controlling the flow of filtered water through the filtered-water conduit from the filter to one of the ice maker and water dispenser.  
     
     
         9 . The water supply system according to  claim 8  and further comprising a sensor for determining the opened/closed status of the valve and coupled to the filter status unit for use in determining the duration of each demand for water.  
     
     
         10 . The water supply system according to  claim 9  wherein the timer comprises a clock coupled to the data processor, the sensor is coupled to the data processor, and the timer determines the duration of each demand of water by using the clock to measure the elapsed time that the valve is opened.  
     
     
         11 . The water supply system according to  claim 10  and further comprising a second valve fluidly connected to the filtered-water conduit for controlling the flow of filtered water through the filtered-water conduit from the filter to the other of the ice maker and water dispenser.  
     
     
         12 . The water supply system according to  claim 11  and further comprising a second sensor for determining the opened/closed status of the second valve and coupled to the filter status unit for use in determining the duration of each demand for water.  
     
     
         13 . The water supply system according to  claim 12  wherein the summing device comprises a portion of the memory in which is stored an accumulated filtered water value.  
     
     
         14 . The water supply system according to  claim 13  wherein the indicator comprises at least one of a visual and an audible indicator.  
     
     
         15 . The water supply system according to  claim 14  wherein the indicator comprises a portion of the memory in which is stored a threshold value for the filter and the data processor for comparing the accumulated filtered water value to the threshold value to determine the status of the filter and activating the one of the visual and audible indicators when the filtered-water volume value reaches the threshold value.  
     
     
         16 . The water supply system according to  claim 1  wherein the water volume meter comprises a sensor for detecting the flow of filtered water from the filter, a timer for determining the duration of filtered water flow detected by the sensor, and a data processor for calculating the volume of filtered water output from the filter for the duration of the detected flow of filtered water.  
     
     
         17 . The water supply system according to  claim 16  wherein the sensor comprises an electrically actuated valve fluidly connected to the filtered-water conduit for controlling the flow of filtered water through the filtered-water conduit from the filter to one of the ice maker and water dispenser and electrically coupled to the data processor and sending a signal to the data processor indicating the open/closed status of the valve.  
     
     
         18 . The water supply system according to  claim 17  wherein the timer comprises a clock coupled to the data processor and determines the duration of the time that the valve is open.  
     
     
         19 . The water supply system according to  claim 18  wherein the sensor further comprises a second electrically actuated valve fluidly connected to the filtered-water conduit for controlling the flow of filtered water through the filtered-water conduit from the filter to the other of the ice maker and water dispenser and electrically coupled to the data processor and sending a signal to the data processor indicating the open/closed status of the second valve.  
     
     
         20 . A refrigerator comprising: 
 a cabinet having a fresh food compartment with an open face and a freezer compartment with an open face;    a first door mounted to the cabinet for selectively closing the open face of fresh food compartment;    a second door mounted to the cabinet for selectively closing the open face of the freezer compartment;    at least one water-using accessory;    a replaceable water filter having an inlet adapted to fluidly connect to a supply of household water and an outlet fluidly connected to the at least one water-using accessory; and;    a filter status unit indicating the replacement status for the replaceable water filter based on the accumulated volume of filtered water supplied by the replaceable water filter.    
     
     
         21 . The refrigerator according to  claim 20  wherein the at least one water-using accessory is one of a water dispenser or an ice maker.  
     
     
         22 . The refrigerator according to  claim 21  wherein the at least one of a water-using accessory is both the water dispenser and the ice maker.  
     
     
         23 . The refrigerator according to  claim 22  and further comprising a valve fluidly connecting at least one of the water dispenser and ice maker to the replaceable filter.  
     
     
         24 . The refrigerator according to  claim 23  and further comprising a second valve fluidly connecting the other of the at least one of the water dispenser and ice maker to the replaceable filter.  
     
     
         25 . The refrigerator according to  claim 20  wherein the filter status unit further comprises a timer that determines the duration of time that filtered water is supplied from the replaceable filter and a filtered-water volume calculator that calculates the filtered-water volume based on the determined duration and the flow rate of the filtered water to the at least one water-using accessory.  
     
     
         26 . The refrigerator according to  claim 25  wherein the timer determines a duration for each supply of filtered water to the at least one water-using accessory, the filtered-water volume calculator calculates a corresponding filtered-water volume for each supply, and the filter status unit further comprises a filtered-water volume summing device that sums the calculated filtered-water volumes for each supply to determine the accumulated volume of filtered water.  
     
     
         27 . The refrigerator according to  claim 26  wherein the filter status unit further comprises a microprocessor having a memory and a clock coupled to the microprocessor and supplying timing data thereto, the microprocessor and the clock form the timer to determine the duration of each supply, the microprocessor forms the filtered-water volume calculator by multiplying the duration by a flow rate stored in the memory, the microprocessor also forms the summing device by calculating and storing in memory a value corresponding to the accumulated volume of filtered water.  
     
     
         28 . The refrigerator according to  claim 27  wherein the at least one water-using accessory comprises first and second water-using accessories.  
     
     
         29 . The refrigerator according to  claim 28  wherein the first water-using accessory has a first water flow rate, the second water-using accessory has a second flow rate, which is different than the first flow rate, and the first and second flow rates are stored in the microprocessor memory and the microprocessor selects the flow rate corresponding to which of the first and second accessories is supplied filtered water by the filter when calculating the water volume supplied by the replaceable filter  
     
     
         30 . The refrigerator according to  claim 29  and the filter status unit further comprises a sensor for determining which of the first and second accessories is being supplied water from the water filter.  
     
     
         31 . The refrigerator according to  claim 30  wherein the sensor comprises at least one valve fluidly connecting one of the first and second accessories to the replaceable filter and the at least one valve is coupled to the microprocessor and provides a signal to the microprocessor indicative of when the at least one valve is open.  
     
     
         32 . The refrigerator according to  claim 31  wherein the sensor comprises a second valve fluidly connecting the other of the first and second accessories to the replaceable filter and the second valve is coupled to the microprocessor and provides a signal to the microprocessor indicative of when the second valve is open.  
     
     
         33 . In a refrigerator comprising at least one water-using accessory with a replaceable filter coupled to a water supply and a water supply system for delivering filtered water from the replaceable filter to the at least one water-using accessory, a filter status unit for determining whether the replaceable filter should be replaced, the filter status unit comprising: 
 a timer that determines the duration of time that filtered water is supplied from the replaceable filter to the at least one water-using appliance;    a filtered-water volume calculator that calculates the filtered-water volume based on the determined duration and the flow rate of the filtered water to the at least one water-using accessory; and    a filtered-water volume summing device for maintaining an accumulated filtered-water volume based on the calculated filtered-water volume.    
     
     
         34 . The filter status unit according to  claim 33  wherein the timer determines a duration for each supply of filtered water to the at least one water-using accessory, the filtered-water volume calculator calculates a corresponding filtered-water volume for each supply.  
     
     
         35 . The filter status unit according to  claim 34  wherein the filtered-water volume summing device sums the calculated filtered-water volumes for each supply to determine the accumulated volume of filtered-water.  
     
     
         36 . The filter status unit according to  claim 35  and further comprises a microprocessor having a memory and a clock coupled to the microprocessor and supplying timing data thereto, the microprocessor and the clock form the timer to determine the duration of each supply, the microprocessor forms the filtered-water volume calculator by multiplying the duration by a flow rate stored in the memory, the microprocessor also forms the summing device by calculating and storing in memory a value corresponding to the accumulated volume of filtered water.  
     
     
         37 . The filter status unit according to  claim 36  wherein the flow rate is approximately equal to the rate at which the at least one water-using appliance draws the filtered water.  
     
     
         38 . The filter status unit according to  claim 36  wherein the at least one water-using accessory comprises first and second water-using accessories.  
     
     
         39 . The filter status unit according to  claim 28  wherein the first water-using accessory has a first water flow rate, the second water-using accessory has a second flow rate, which is different than the first flow rate, and the first and second flow rates are stored in the microprocessor memory and the microprocessor selects the flow rate corresponding to which of the first and second accessories is supplied filtered water by the filter when calculating the water volume supplied by the replaceable filter.  
     
     
         40 . The filter status unit according to  claim 39  wherein the filter status unit further comprises a sensor for determining which of the first and second accessories is being supplied water from the water filter.  
     
     
         41 . The filter status unit according to  claim 40  wherein the sensor comprises at least one valve for fluidly connecting one of the first and second accessories to the replaceable filter and the at least one valve is coupled to the microprocessor and provides a signal to the microprocessor indicative of when the at least one valve is open for use by the microprocessor in determining the duration of the supply.  
     
     
         42 . The filter status unit according to  claim 41  wherein the sensor further comprises a second valve fluidly connecting the other of the first and second accessories to the replaceable filter and the second valve is coupled to the microprocessor and provides a signal to the microprocessor indicative of when the second valve is open for use by the microprocessor in determining the duration of the supply.  
     
     
         43 . The filter status unit according to  claim 36  and further comprising an indicator that sends a signal observable by a user that the replaceable filter needs replacing.  
     
     
         44 . The filter status unit according to  claim 43  wherein the indicator comprises at least one of a visual and an audible indicator.  
     
     
         45 . The filter status unit according to  claim 44  wherein the indicator comprises a portion of the memory in which is stored a threshold value for the filter and the microprocessor compares the accumulated filtered water value to the threshold value to determine the status of the filter and activates the at least one of the visual and audible indicators when the filtered-water volume value reaches the threshold value.