US3850574A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Atmospheric furnace apparatus
Assignee: Tokyo Heat Treating Co
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Filing: 1973-04-09
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Granted: 1974-11-26
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Expires: 1993-04-09
Abstract
Abstract A gas atmospheric furnace is provided which is used for carburizing or carbonitriding treatment of steel articles. A gas inlet for introducing an atmosphere gas into the furnace communicates with a passageway formed around the shaft of a fan which is used to agitate the gas. A different kind of gas is also introduced into the gas inlet through the same passageway. Another gas inlet is disposed in opposing relationship with the first mentioned gas inlet, and gases supplied through both gas inlets serve to maintain the temperature within the furnace constant.
Inventors
- 👤 K Namba
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 18:36
CPC Classifications
C; C21; C21D; C21D1/00; C21D1/74; C21D1/767
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
111 words
A gas atmospheric furnace for carburizing and carbonitriding treatment of steel articles comprising a first gas inlet for introducing an atmosphere gas into the furnace under forced pressure, a fan for stirring the atmosphere gas introduced by said first gas inlet, said first gas inlet leading into a passageway formed along and around the shaft of the fan, and a second gas inlet located on the opposite side of the furnace from the first gas inlet, ,said second gas inlet introducing an atmosphere gas of normal temperature to cool the then relatively elevated gas adjacent the second gas inlet to thus maintain an even temperature of the gases within the furnace.
Claim 2
Dependent Claim
111 words
A gas atmospheric furnace for carburizing and carbonitriding treatment of steel articles comprising a first gas inlet for introducing an atmosphere gas into the furnace under forced pressure, a fan for stirring the atmosphere gas introduced by said first gas inlet, said first gas inlet leading into a passageway formed along and around the shaft of the fan, and a second gas inlet located on the opposite side of the furnace from the first gas inlet, ,said second gas inlet introducing an atmosphere gas of normal temperature to cool the then relatively elevated gas adjacent the second gas inlet to thus maintain an even temperature of the gases within the furnace.
Claim 3
Dependent Claim
33 words
A gas atmospheric furnace according to claim 1, further including a guide pipe connected with the passage way for conducting the atmosphere gas from the first gas inlet therethrough to the passage way.
Claim 4
Dependent Claim
24 words
A gas atmospheric furnace according to claim 2, further including another guide pipe, the two guide pipes conducting different gases to the passage way.
Claim 5
Dependent Claim
27 words
A gas atmospheric furnace according to claim 1 in which said second gas inlet is connected with a gas supply system through a flow rate control valve.
Claim 6
Dependent Claim
48 words
A gas atmospheric furnace according to claim 1, further including a gas flow deflector located within the furnace adjacent to said second gas inlet to direct the gas entering said inlet to a desired location in said furnace to recover or maintain the thermal balance of gases therein.
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 |