US3959979A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Dual voltage forced air heat exchanger
Assignee: Ardco Inc
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Filing: 1974-12-09
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Granted: 1976-06-01
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Expires: 1994-12-09
Abstract
Abstract This patent describes forced air heat exchangers using single phase A. C. motors to drive their fans and a method of securing high and low speed operation of the motors by connecting them alternately in delta and wye across a 3-phase power supply.
Inventors
- 👤 Daniel E. Kramer
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 16:10
CPC Classifications
F; F25; F25B; F25B39/00; F25B39/04; F25B49/00; F25B49/02; F25B2600/00; F25B2600/11; F25B2600/111; F25B2600/112; Y; Y02; Y02B; Y02B30/00; Y02B30/70
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
164 words
A method of achieving two speed operation of fans in a forced air heat exchanger, said heat exchanger having a heat exchange element; fans positioned to move air over said element; alternating current motors adapted to drive said fans, said motors being of the type which operate at higher voltage, higher speed, lower voltage, lower speed; said motors having first power connection means and second power connection means; a common connection; multipole switch means having a first and a second position, said switch means being connected to the common connection, wherein the method comprises providing a poly-phase power supply having at least 3 conductors; connecting the conductors to the switch means; essentially equally distributing connection of first power connection means among at least two conductors; actuating the switch means to connect the second power connection means alternately to the conductors, causing the motors to operate at higher voltage, higher speed; and to the common, causing the motors to operate at lower voltage, lower speed.
Claim 2
Independent Claim
164 words
A method of achieving two speed operation of fans in a forced air heat exchanger, said heat exchanger having a heat exchange element; fans positioned to move air over said element; alternating current motors adapted to drive said fans, said motors being of the type which operate at higher voltage, higher speed, lower voltage, lower speed; said motors having first power connection means and second power connection means; a common connection; multipole switch means having a first and a second position, said switch means being connected to the common connection, wherein the method comprises providing a poly-phase power supply having at least 3 conductors; connecting the conductors to the switch means; essentially equally distributing connection of first power connection means among at least two conductors; actuating the switch means to connect the second power connection means alternately to the conductors, causing the motors to operate at higher voltage, higher speed; and to the common, causing the motors to operate at lower voltage, lower speed.
Claim 3
Dependent Claim
16 words
A method as in claim 1 where the common is connected to a system neutral conductor.
Claim 4
Dependent Claim
70 words
A method as in claim 1 where the forced air heat exchanger is an evaporator in a refrigeration system, said system having a compressor with on and off conditions, and the switch is actuated in essential correspondence with said on-off conditions; whereby the motors are caused to operate at higher speed when the compressor is in its on condition and lower speed when the compressor is in its off condition.
Claim 5
Dependent Claim
28 words
A method as in claim 1 where the forced air heat exchanger is a condenser in a refrigeration system, including a control operatively positioned to actuate the switch.
Claim 6
Dependent Claim
23 words
A method as in claim 4 where the control is selected from the group consisting of photocell, thermostat, timer and sound level detector.
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) | 1979-06-01 | 1979-12-01 | 1980-06-01 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1983-06-01 | 1983-12-01 | 1984-06-01 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1987-06-01 | 1987-12-01 | 1988-06-01 | $7700.00 | Window Closed / Lapsed |