Patent US3851148A successfully refreshed from Google Patents.
US3851148A
Expired / Lapsed
US
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Power control method and apparatus
Assignee: WESTERN STRESS RELIEVING SERVICES Inc CA
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Filing: 1973-09-18
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Granted: 1974-11-26
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Expires: 1993-09-18
Abstract
Abstract A power control method and apparatus for weld stress relief employ first and second voltage control means for supplying different control voltages to a saturable reactor for regulating the supply of power to heaters. By sensing the temperatures of different workpiece zones to provide temperature signals, switch means are automatically actuated when the temperature signals differ by a predetermined amount and thereby the voltage to the saturable reactor is changed, by changing over from one to the other of the voltage control means, and simultaneously one of the heaters is de-energized.
Inventors
- 👤 H Schonert
- 👤 R Jones
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-04 06:27
CPC Classifications
B; B23; B23K; B23K11/00; B23K11/24; B23K11/248; B23K9/00; B23K9/235; C; C21; C21D; C21D9/00; C21D9/50; G; G05; G05D; G05D23/00; G05D23/19; G05D23/1902; G05D23/1904; G05D23/20; G05D23/22; G05D23/2236; G05D23/224
Claims Analysis
Total Claims: 19
Claim 1
Independent Claim
262 words
Power supply and control apparatus for pre-weld heating and weld stress relief, comprising: a. first and second electrical resistance heating elements; b. means for connecting said first and second electrical resistance heating elements in series with one another for heating different workpiece zones; c. a power input transformer for supplying electrical power to said first and second electrical resistance heating elements; d. a saturable reactor connected between said transformer and said first and second electrical resistance heating elements for controlling the supply of electrical power from said transformer to said first and second electrical resistance heating elements; e. first voltage control means for providing a first control voltage to said saturable reactor to provide a predetermined electrical power to said first and second electrical resistance heating elements; f. second voltage control means for providing a second control voltage to said saturable reactor to control said saturable reactor for providing a lower electrical power to said first electrical resistance heating element; g. first and second temperature responsive means respectively associated with said first and second electrical resistance heating elements for providing temperature signals corresponding to the temperatures of the respective workpiece zones of said first and second electrical resistance heating elements; h. means for comparing the temperature signals from said first and second temperature responsive means and providing an output signal when the difference between the temperature signals exceeds a predetermined amount; and i. switch means responsive to said output signal for disconnecting said first voltage control means from said saturable reactor and connecting said second voltage control means to said saturable reactor.
Claim 2
Dependent Claim
262 words
Power supply and control apparatus for pre-weld heating and weld stress relief, comprising: a. first and second electrical resistance heating elements; b. means for connecting said first and second electrical resistance heating elements in series with one another for heating different workpiece zones; c. a power input transformer for supplying electrical power to said first and second electrical resistance heating elements; d. a saturable reactor connected between said transformer and said first and second electrical resistance heating elements for controlling the supply of electrical power from said transformer to said first and second electrical resistance heating elements; e. first voltage control means for providing a first control voltage to said saturable reactor to provide a predetermined electrical power to said first and second electrical resistance heating elements; f. second voltage control means for providing a second control voltage to said saturable reactor to control said saturable reactor for providing a lower electrical power to said first electrical resistance heating element; g. first and second temperature responsive means respectively associated with said first and second electrical resistance heating elements for providing temperature signals corresponding to the temperatures of the respective workpiece zones of said first and second electrical resistance heating elements; h. means for comparing the temperature signals from said first and second temperature responsive means and providing an output signal when the difference between the temperature signals exceeds a predetermined amount; and i. switch means responsive to said output signal for disconnecting said first voltage control means from said saturable reactor and connecting said second voltage control means to said saturable reactor.
Claim 3
Dependent Claim
49 words
Power supply and control apparatus as claimed in claim 1, and further comprising means responsive to said output signal for short-circuiting one of said first and second electrical resistance heating elements to thereby interrupt heating of the hottest of said workpiece zones by said one of said heating elements.
Claim 4
Dependent Claim
32 words
Power supply and control apparatus as claimed in claim 2, and further comprising means for variably regulating the first and second control voltages to vary the power supplied through said saturable reactor.
Claim 5
Dependent Claim
78 words
Power supply and control apparatus as claimed in claim 3, wherein said regulating means comprise signal generator means for generating a demand signal which varies in accordance with a predetermined heating programme, error signal means for comparing said demand signal with the temperature signal of said second temperature responsive device, to provide an error signal, and switch means responsive to the error signal for controlling the connection of the first and second control voltages to said saturable reactor.
Claim 6
Dependent Claim
24 words
Power supply and control apparatus as claimed in claim 4, further comprising integrator means connected between said error signal means and said switch means.
Claim 7
Dependent Claim
49 words
Power supply and control apparatus as claimed in claim 4, wherein said demand signal generating means comprise pulse dividing means for producing a plurality of pulse trains of different frequencies, and binary counter means responsive to said pulse trains for varying the demand signal as a function of time.
Claim 8
Dependent Claim
33 words
Power supply and control apparatus as claimed in claim 6, wherein rate select means for adjustably controlling the rate of variation of the demand signal are operatively associated with said binary counter means.
Claim 9
Dependent Claim
74 words
Power supply and control apparatus as claimed in claim 6, further comprising adjustable means for generating a preselectable soak temperature signal, means responsive to equalization of said soak temperature signal and said demand signal for applying a soak signal to stop said binary counter, a pulse counter responsive to said soak signal for initiating countdown of said binary counter means, and means for supplying pulses from said pulse dividng means to said pulse counter.
Claim 10
Dependent Claim
39 words
Power supply and Control apparatus as claimed in claim 6, further comprising means responsive to equalization of said demand signal and one of said temperature signals for initiating the variation of said demand signal by said binary counter means.
Claim 11
Dependent Claim
50 words
Power supply and control apparatus as claimed in claim 4, wherein said temperature signal comparing means comprise a differential amplifier having a pair of inputs, and first and second sample and hold means are provided for respectively connecting said first and second temperature responsive means to said pair of inputs.
Claim 12
Dependent Claim
50 words
Power supply and control apparatus as claimed in claim 2, wherein said temperature signal comparing means comprise a differential amplifier having a pair of inputs, and first and second sample and hold means are provided for respectively connecting said first and second temperature responsive means to said pair of inputs.
Claim 13
Dependent Claim
49 words
Power supply and control apparatus as claimed in claim 11, wherein said demand signal generating means comprise pulse dividing means for producing a plurality of pulse trains of different frequencies, and binary counter means responsive to said pulse trains for varying the demand signal as a function of time.
Claim 14
Dependent Claim
74 words
Power supply and control apparatus as claimed in claim 12, further comprising adjustable means for generating a preselectable soak temperature signal, means responsive to equalization of said soak temperature signal and said demand signal for applying a soak signal to stop said binary counter, a pulse counter responsive to said soak signal for initiating countdown of said binary counter means, and means for supplying pulses from said pulse dividing means to said pulse counter.
Claim 15
Dependent Claim
39 words
Power supply and control apparatus as claimed in claim 12, further comprising means responsive to equalization of said demand signal and one of said temperature signals for initiating the variation of said demand signal by said binary counter means.
Claim 16
Dependent Claim
22 words
Power supply and control apparatus as claimed in claim 2, wherein said first and second voltage control means comprise variable auto transformers.
Claim 17
Independent Claim
151 words
A method of controlling a power supply to a pair of heating elements connected in series with one another, comprising the steps of: energizing said heating elements to heat respective workpiece zones, sensing the temperatures of the workpiece zones to provide temperature signals corresponding to the temperatures of the respective zones, providing two different voltages and using one of said voltage to control a saturable reactor for regulating the power supplied to the heating elements, comparing the temperature signals with one another, automatically initiating short circuiting of the power supply across one of the heating elements when one of the temperature signals exceeds the other by a predetermined amount, and simultaneously discontinuing the use of said one voltage and initiating the use of the other of the voltages for controlling the saturable reactor to thereby adjust the power supply to the remaining heating element to compensate for the reduction in load.
Claim 18
Independent Claim
151 words
A method of controlling a power supply to a pair of heating elements connected in series with one another, comprising the steps of: energizing said heating elements to heat respective workpiece zones, sensing the temperatures of the workpiece zones to provide temperature signals corresponding to the temperatures of the respective zones, providing two different voltages and using one of said voltage to control a saturable reactor for regulating the power supplied to the heating elements, comparing the temperature signals with one another, automatically initiating short circuiting of the power supply across one of the heating elements when one of the temperature signals exceeds the other by a predetermined amount, and simultaneously discontinuing the use of said one voltage and initiating the use of the other of the voltages for controlling the saturable reactor to thereby adjust the power supply to the remaining heating element to compensate for the reduction in load.
Claim 19
Dependent Claim
120 words
A method as claimed in claim 16, which includes generating a demand signal representing the required temperature of one of the zones, comparing the corresponding temperature signal with said demand signal to provide an error signal, employing the error signal to control the application of one of said voltages to said saturable reactor, varying the demand signal at a preselected rate of variation, generating a predetermined soak signal representing a desired workpiece soak temperature, comparing the soak signal and the demand signal to discontinue the variation of the demand signal on equalization of the demand and soak signals and to simultaneously initiate a timing operation, and initiating a decreasing variation of the demand signal on completion of the timing operation.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1977-11-25 | 1978-05-27 | 1978-11-26 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-11-25 | 1982-05-27 | 1982-11-26 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-11-25 | 1986-05-27 | 1986-11-26 | $7700.00 | Window Closed / Lapsed |