Patent US3560712A successfully refreshed from Google Patents.
US3560712A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Stress-relieving apparatus
Assignee: G AND G CO
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Filing: 1969-05-19
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Granted: 1971-02-02
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Expires: 1989-05-19
Abstract
Abstract Apparatus for automatically controlling the flow of electric current to a plurality of electric heater units to selectively control the rate at which structure related to each heater unit is heated; to maintain the structure to be heated at a predetermined maximum temperature for a predetermined period of time and to control the rate at which the structure is cooled, said apparatus including a variable power supply unit for each heater unit, temperature sensing means related to the structure to be heated by each heater unit and control means between the power supply unit and the temperature sensing means including a manually adjustable timed programmer and recorder and adjustable means related to the power supply units and under control the timed programmer.
Inventors
- 👤 George G Toohill
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 11:54
CPC Classifications
G; G05; G05D; G05D23/00; G05D23/19; G05D23/1927; G05D23/193; G05D23/1932; G05D23/1934; G05B; G05B19/00; G05B19/02; G05B19/04
Claims Analysis
Total Claims: 4
Claim 1
Independent Claim
338 words
A heat treating apparatus comprising a multiplicity of resistance heaters adapted to be related to work pieces, temperature sensing devices related to each heater and its related work piece, a transformer-type power pack for each heater with power operated drive means to increase and decrease the output thereof, a common multipoint temperature recorder connected with the temperature sensing devices and having commutator means for receiving signals from said devices and distributing said signals in predetermined sequential order to predetermined recording circuits, control means related to the recorder and to the power packs to automatically increase and decrease the power output of the power packs whereby the rate of temperature increase of the work pieces related thereto is maintained at a predetermined set rate, said control means including a pair of normally open relay switches related to each power pack and connected with the drive means thereof are adapted to operate the drive means to increase power pack output and that other connected with the drive means to decrease power pack output, a rate set circuit related to each power pack and a related recording circuit and having a first portion adapted to intermittently receive and hold the temperature signal for a predetermined time period and to compare that signal with the true signal at the end of the time period and to discharge a rate signal, the value of which is proportioned to the rate of change during said time period, a second portion including a manually adjustable potentiometer discharging a rate set signal, a signal comparator receiving the rate and rAte set signals and discharging a demand signal which is of one polarity if the rate of temperature change is above and a signal of opposite polarity if the rate of temperature increase is below the set rate and switching means receiving the demand signal and connected with the pair of relays and adapted to effect closing and opening of said relays and resulting increase and/or decrease of power pack output in response to the demand signal.
Claim 2
Dependent Claim
338 words
A heat treating apparatus comprising a multiplicity of resistance heaters adapted to be related to work pieces, temperature sensing devices related to each heater and its related work piece, a transformer-type power pack for each heater with power operated drive means to increase and decrease the output thereof, a common multipoint temperature recorder connected with the temperature sensing devices and having commutator means for receiving signals from said devices and distributing said signals in predetermined sequential order to predetermined recording circuits, control means related to the recorder and to the power packs to automatically increase and decrease the power output of the power packs whereby the rate of temperature increase of the work pieces related thereto is maintained at a predetermined set rate, said control means including a pair of normally open relay switches related to each power pack and connected with the drive means thereof are adapted to operate the drive means to increase power pack output and that other connected with the drive means to decrease power pack output, a rate set circuit related to each power pack and a related recording circuit and having a first portion adapted to intermittently receive and hold the temperature signal for a predetermined time period and to compare that signal with the true signal at the end of the time period and to discharge a rate signal, the value of which is proportioned to the rate of change during said time period, a second portion including a manually adjustable potentiometer discharging a rate set signal, a signal comparator receiving the rate and rAte set signals and discharging a demand signal which is of one polarity if the rate of temperature change is above and a signal of opposite polarity if the rate of temperature increase is below the set rate and switching means receiving the demand signal and connected with the pair of relays and adapted to effect closing and opening of said relays and resulting increase and/or decrease of power pack output in response to the demand signal.
Claim 3
Dependent Claim
122 words
An apparatus as set forth in claim 1 which further includes heat limit means to limit the maximum temperature to which the pieces of work are brought to and including a normally closed power control relay controlling the power to each power pack, a manually adjustable potentiometer discharging a set temperature reference signal, a signal comparator receiving said reference signal and receiving the signal from the related recording circuit and adapted to discharge an operating signal of predetermined value when the reference signal and signal from the recording circuit reach a predetermined ratio, and switching means controlled by said operating signal and controlling the operation of the power control relay to open said power control relay when the set temperature is reached.
Claim 4
Dependent Claim
190 words
An apparatus as set forth in claim 1 which further includes heat limit means to limit the maximum temperature to which the pieces of work are brought to and including a normally closed power control relay controlling the power to each power pack, a manually adjustable potentiometer discharging a set temperature reference signal, a signal comparator receiving said reference signal and receiving the signal from the related recording circuit and adapted to discharge an operating signal of predetermined value when the reference signal and signal from the recording circuit reach a predetermined ratio, and switching means controlled by said operating signal and controlling the operation of the power control relay to open said power control relay when the set temperature is reached, said switching means controlling the operation of the power control relay being connected with the control means to receive said demand signal and having timing means related thereto whereby said demand signal effects opening of the power control relay when operation of the first-mentioned pair of relays fails to decrease power pack output sufficiently to maintain the set rate of heat increase during a set period of time.
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) | 1974-02-01 | 1974-08-03 | 1975-02-02 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-02-01 | 1978-08-03 | 1979-02-02 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-02-01 | 1982-08-03 | 1983-02-02 | $7700.00 | Window Closed / Lapsed |