US3702030A
Expired / Lapsed
US
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Digital dryer control circuit
Assignee: Whirlpool Corp
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Filing: 1971-03-29
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Granted: 1972-11-07
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Expires: 1991-03-29
Abstract
Abstract A fabric treating apparatus, such as a domestic clothes dryer, is provided with a digital control circuit and a sensor system which cooperate to terminate a fabric treatment operation when the fabric has reached a desired condition. A digital counter receives and accumulates pulses from a reference source and is repetitively reset by signals from a sensor circuit which provides reset pulses at a rate dependent upon the dryness condition of the fabric load. As the fabric load approaches the desired dryness condition the interval between reset pulses increases, thus allowing the counter to accumulate successively greater counts before being reset, until eventually a preselected count is accumulated which triggers circuitry to terminate the fabric drying operation. After termination of the drying operation the counter serves as a clock and operates in conjunction with an indexable digital memory and associated logic circuitry to control a program of subsequent fabric treatment operations.
Inventors
- 👤 Donald E Janke
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 10:59
CPC Classifications
D; D06; D06B; D06B1/00; D06F; D06F34/00; D06F34/08; D06F58/00; D06F58/32; D06F58/34; D06F58/36; D06F58/38; D06C; D06C2700/00; D06C2700/13; D06C2700/135; D06F2103/00; D06F2103/02; D06F2103/08; D06F2103/10; D06F2103/38; D06F2105/00; D06F2105/28; D06F2105/62
Claims Analysis
Total Claims: 15
Claim 1
Independent Claim
62 words
A control circuit for a dryer, comprising: a source of timing pulses; a first resettable counter arranged to count said pulses; moisture sensing means operative to sense the moisture content of the clothes load and reset said counter at a rate proportional to the sensed moisture content; and control logic means for terminating the drying operation upon accumulation of a preselected count.
Claim 2
Dependent Claim
62 words
A control circuit for a dryer, comprising: a source of timing pulses; a first resettable counter arranged to count said pulses; moisture sensing means operative to sense the moisture content of the clothes load and reset said counter at a rate proportional to the sensed moisture content; and control logic means for terminating the drying operation upon accumulation of a preselected count.
Claim 3
Dependent Claim
90 words
The control circuit of claim 1, wherein said moisture sensing means comprises: an oscillator circuit operative to produce pulses at a predetermined frequency; conductivity sensing means arranged to contact the fabric load and connected to said oscillator so as to prevent generation of oscillator pulses in response to contact with fabric having a conductivity greater than a predetermined amount; and, circuit means for receiving said oscillator pulses and producing a reset pulse for said first counter whenever the time between pulses from said oscillator is greater than a predetermined interval.
Claim 4
Dependent Claim
60 words
The control circuit of claim 2, wherein said circuit means for producing a reset pulse comprises a second resettable counter connected To count pulses from said source of timing pulses, and having a reset input arranged to receive said oscillator pulses and an output arranged to reset said first counter upon accumulation of a predetermined number of said timing pulses.
Claim 5
Dependent Claim
24 words
The control circuit of claim 1, further including means for selectively adjusting said preselected count which must be accumulated to terminate said drying operation.
Claim 6
Dependent Claim
31 words
The control circuit of claim 1, wherein said source of timing pulses comprises pulse derivation circuit means for utilizing the AC power line voltage to generate pulses synchronized to said voltage.
Claim 7
Dependent Claim
51 words
The control circuit of claim 1, further including: an indexable memory circuit having a series of sequential states corresponding to a program of dryer operations; and logic circuit means connected to said memory circuit for indexing same and providing dryer control output signals in accordance with the state of said memory.
Claim 8
Dependent Claim
101 words
In fabric treatment apparatus having means defining a fabric treatment zone and means for treating fabric placed therein to a predetermined condition, a control for terminating said treatment operation comprising: a source of timing signals; a counter arranged to count pulses derived from said source of timing signals; sensing means associated with said fabric treatment zone for sensing a parameter related to said predetermined fabric condition and operative to reset said counter at a rate dependent upon the level of said sensed parameter; AND circuit means for terminating said fabric treatment operation in response to the accumulation of a preselected count.
Claim 9
Dependent Claim
101 words
In fabric treatment apparatus having means defining a fabric treatment zone and means for treating fabric placed therein to a predetermined condition, a control for terminating said treatment operation comprising: a source of timing signals; a counter arranged to count pulses derived from said source of timing signals; sensing means associated with said fabric treatment zone for sensing a parameter related to said predetermined fabric condition and operative to reset said counter at a rate dependent upon the level of said sensed parameter; AND circuit means for terminating said fabric treatment operation in response to the accumulation of a preselected count.
Claim 10
Independent Claim
85 words
A method of controlling a fabric treating apparatus having a treatment zone and means for effecting at least one fabric treating operation, comprising the steps of: a. initiating a fabric treating operation; b. sensing a parameter related to the condition of the fabric within the treatment zone; c. counting pulses from a source of timing signals; d. repeatedly terminating and restarting the count until said sensed parameter reaches a predetermined value; and, e. terminating the fabric treating operation upon the accumulation of a preselected count.
Claim 11
Independent Claim
85 words
A method of controlling a fabric treating apparatus having a treatment zone and means for effecting at least one fabric treating operation, comprising the steps of: a. initiating a fabric treating operation; b. sensing a parameter related to the condition of the fabric within the treatment zone; c. counting pulses from a source of timing signals; d. repeatedly terminating and restarting the count until said sensed parameter reaches a predetermined value; and, e. terminating the fabric treating operation upon the accumulation of a preselected count.
Claim 12
Independent Claim
78 words
A method of controlling a fabric drying apparatus having means for drying fabric placed therein, comprising the steps of: a. initiating a fabric drying operation; b. sensing the moisture content of the fabric load; c. counting pulses from a source of timing signals; d. repeatedly terminating and restarting the count in response to a sensed moisture content greater than a predetermined amount; and e. terminating the fabric drying operation in response to the accumulation of a preselected count.
Claim 13
Independent Claim
78 words
A method of controlling a fabric drying apparatus having means for drying fabric placed therein, comprising the steps of: a. initiating a fabric drying operation; b. sensing the moisture content of the fabric load; c. counting pulses from a source of timing signals; d. repeatedly terminating and restarting the count in response to a sensed moisture content greater than a predetermined amount; and e. terminating the fabric drying operation in response to the accumulation of a preselected count.
Claim 14
Dependent Claim
36 words
The method according to claim 9, wherein the step of counting pulses includes: a. generating pulses which are derived from the AC power line voltage; and, b. counting said pulses by means of a digital counter.
Claim 15
Dependent Claim
42 words
The method according to claim 9 further including the steps of: f. providing a sequence of digital function signals corresponding to a program of fabric treating functions; and, g. controlling the energization of said fabric drying means in accordance with said signals.
References Cited (Backward Citations)
US3471938A
Cited
US3474545A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1975-11-07 | 1976-05-08 | 1976-11-07 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-11-07 | 1980-05-08 | 1980-11-07 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-11-07 | 1984-05-08 | 1984-11-07 | $7700.00 | Window Closed / Lapsed |