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US4697293A Expired / Lapsed US ⏱️ 0.0 years remaining

Pressure sensing automatic water level control

Assignee: Whirlpool Corp
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Filing: 1985-12-31
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Granted: 1987-10-06
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Expires: 2005-12-31
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Abstract

Abstract A liquid control system is provided for an automatic washer which responds to a user's input of fabric type to introduce into the tub of the washer an optimum volume of liquid to wash a clothes load in the tub based on sensed pressure wave changes as the tub is filled and agitated simultaneously.

Inventors

  • 👤 Donald E. Knoop

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-10-26 17:42
CPC Classifications
D; D06; D06F; D06F39/00; D06F39/08; D06F39/087; D06F2101/00; D06F2101/02; D06F2101/06; D06F2103/00; D06F2103/18; D06F2105/00; D06F2105/02; D06F34/00; D06F34/14; D06F34/18; Y; Y10; Y10T; Y10T137/00; Y10T137/7287; Y10T137/729

Claims Analysis

Total Claims: 21
Claim 1
Independent Claim 138 words
An automatic washing machine having a tub to receive washing liquid and a load of clothes to be washed therein including an automatic liquid fill control system comprising: supply means for supplying wash liquid to said tub; means for measuring the head pressure of liquid in said tub; means for agitating said liquid in said tub in an oscillatory manner to create pressure waves; means for measuring the varying pressure of said pressure waves; means for determining and storing the range of varying pressures of said pressure waves; means for comparing a currently determined range with a stored largest range; means for determining the optimum total volume of liquid required for washing said clothes load based on the pressure range comparison, and means for automatically controlling said supply means for admitting desired volumes of water into said tub.
Claim 2
Dependent Claim 138 words
An automatic washing machine having a tub to receive washing liquid and a load of clothes to be washed therein including an automatic liquid fill control system comprising: supply means for supplying wash liquid to said tub; means for measuring the head pressure of liquid in said tub; means for agitating said liquid in said tub in an oscillatory manner to create pressure waves; means for measuring the varying pressure of said pressure waves; means for determining and storing the range of varying pressures of said pressure waves; means for comparing a currently determined range with a stored largest range; means for determining the optimum total volume of liquid required for washing said clothes load based on the pressure range comparison, and means for automatically controlling said supply means for admitting desired volumes of water into said tub.
Claim 3
Dependent Claim 52 words
A device according to claim 1 including means for measuring the rate at which liquid is being supplied to the tub during agitation and means for interrupting and restarting agitation to permit additional liquid to be supplied to the tub without agitation during periods of low liquid levels and long fill times.
Claim 4
Dependent Claim 41 words
A device according to claim 1, wherein said means for measuring the head pressure and means for measuring the varying pressure of the pressure waves comprises means for sampling the pressure of the liquid exerted against a portion of said tub.
Claim 5
Dependent Claim 28 words
A device according to claim 1, wherein said means for automatically controlling said supply means includes means for controlling valves in water supply lines connected to said tub.
Claim 6
Dependent Claim 16 words
A device according to claim 1 including means for inputting fabric type of said clothes load.
Claim 7
Dependent Claim 34 words
A device according to claim 5, wherein said means for determining the optimum total volume of liquid requirement for wash said clothes load is dependent on said pressure range comparison and said fabric type.
Claim 8
Dependent Claim 34 words
A device according to claim 1, wherein said means for measuring the varying pressures comprises a pressure sensor which provides an electrical square wave output having a period inversely proportional to the pressure sensed.
Claim 9
Dependent Claim 26 words
A device according to claim 7, wherein said means for determining a range of pressures includes means for determining the period of said electrical square waves.
Claim 10
Dependent Claim 110 words
In a machine for liquid treatment of materials a liquid control system comprising: a container for receiving said materials; means for adding liquid to said container; means for determining the amount of liquid added to said container; means for agitating said liquid in said container to cause pressure waves; means for determining and storing the range of varying pressures of said pressure waves; means for comparing a current range with a previously stored largest range; means for determining an optimum value of additional liquid to be added based on the amount of liquid previously added and differences in pressure ranges; and means for introducing said additional liquid into said container.
Claim 11
Dependent Claim 110 words
In a machine for liquid treatment of materials a liquid control system comprising: a container for receiving said materials; means for adding liquid to said container; means for determining the amount of liquid added to said container; means for agitating said liquid in said container to cause pressure waves; means for determining and storing the range of varying pressures of said pressure waves; means for comparing a current range with a previously stored largest range; means for determining an optimum value of additional liquid to be added based on the amount of liquid previously added and differences in pressure ranges; and means for introducing said additional liquid into said container.
Claim 12
Dependent Claim 18 words
A system according to claim 9, wherein said means for agitation comprises a vaned oscillating vertical axis agitator.
Claim 13
Dependent Claim 52 words
A device according to claim 9 including means for measuring the rate at which liquid is being supplied to the tub during agitation and means for interrupting and restarting agitation to permit additional liquid to be supplied to the tub without agitation during periods of low liquid levels and long fill times.
Claim 14
Dependent Claim 41 words
A device according to claim 9, wherein said means for measuring the head pressure and means for measuring the varying pressure of the pressure waves comprises means for sampling the pressure of the liquid exerted against a portion of said tub.
Claim 15
Dependent Claim 28 words
A device according to claim 9, wherein said means for automatically controlling said supply means includes means for controlling valves in water supply lines connected to said tub.
Claim 16
Dependent Claim 16 words
A device according to claim 9 including means for inputing fabric type of said clothes load.
Claim 17
Dependent Claim 34 words
A device according to claim 14, wherein said means for determining the optimum total volume of liquid requirement for wash said clothes load is dependant on said pressure range comparison and said fabric type.
Claim 18
Dependent Claim 34 words
A device according to claim 9, wherein said means for measuring the varying pressures comprises a pressure sensor which provides an electrical square wave output having a period inversely proportional to the pressure sensed.
Claim 19
Dependent Claim 26 words
A device according to claim 16, wherein said means for determining a range of pressures includes means for determining the period of said electrical square waves.
Claim 20
Independent Claim 119 words
A method of controlling the amount of liquid in a liquid treatment machine comprising: placing a specific mass of material to be treated in a container in the machine; filling the machine with liquid; agitating the material and liquid in the container during the filling step in an oscillatory manner; measuring the head pressure of the liquid during the agitating step; determining and storing the range of pressures during periods of oscillation; comparing a current range with a previously stored largest range; calculating an optimum value of additional liquid to be added based on the amount of liquid in the container and the differences in pressure ranges, and introducing additional liquid in an amount to achieve said optimum value.
Claim 21
Independent Claim 119 words
A method of controlling the amount of liquid in a liquid treatment machine comprising: placing a specific mass of material to be treated in a container in the machine; filling the machine with liquid; agitating the material and liquid in the container during the filling step in an oscillatory manner; measuring the head pressure of the liquid during the agitating step; determining and storing the range of pressures during periods of oscillation; comparing a current range with a previously stored largest range; calculating an optimum value of additional liquid to be added based on the amount of liquid in the container and the differences in pressure ranges, and introducing additional liquid in an amount to achieve said optimum value.

USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 1990-10-05 1991-04-06 1991-10-06 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 1994-10-05 1995-04-06 1995-10-06 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 1998-10-05 1999-04-06 1999-10-06 $7700.00 Window Closed / Lapsed

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