US3998441A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Furnace for tempering and hardening workpieces
Assignee: Evonik Operations GmbH
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Filing: 1976-05-24
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Granted: 1976-12-21
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Expires: 1996-05-24
Abstract
Abstract There is provided a furnace for tempering and hardening workpieces comprising an annealing chamber and a quenching chamber constructed as a fluidized bed, the quenching chamber is arranged below the annealing chamber, the fluidized bed which is stationary during the annealing treatment serves as bottom temperature insulation for the annealing chamber, and the lateral heat insulation of the annealing chamber is extended to below the surface of the stationary fluidized bed.
Inventors
- 👤 Rolf Schuster
- 👤 Erwin Schumann
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 06:39
CPC Classifications
C; C21; C21D; C21D1/00; C21D1/62; C21D1/34; C21D1/53; C21D1/74; C21D1/773
Claims Analysis
Total Claims: 5
Claim 1
Independent Claim
101 words
A furnace suitable for annealing and quenching workpieces comprising an annealing chamber and a quenching chamber disposed vertically below said annealing chamber, said quenching chamber containing a fluidizable bed of solid particles which, when in stationary position, serves as thermal insulation for the bottom of said furnace, means for introducing fluidizing gas into the quenching chamber during the quenching of the workpiece and for preventing the introduction of said gas during annealing of a workpiece and lateral heat insulation on the annealing chamber extending below the upper surface of the fluidized bed when said bed is not in the fluidized condition.
Claim 2
Dependent Claim
101 words
A furnace suitable for annealing and quenching workpieces comprising an annealing chamber and a quenching chamber disposed vertically below said annealing chamber, said quenching chamber containing a fluidizable bed of solid particles which, when in stationary position, serves as thermal insulation for the bottom of said furnace, means for introducing fluidizing gas into the quenching chamber during the quenching of the workpiece and for preventing the introduction of said gas during annealing of a workpiece and lateral heat insulation on the annealing chamber extending below the upper surface of the fluidized bed when said bed is not in the fluidized condition.
Claim 3
Dependent Claim
11 words
A furnace according to claim 1 which is a vacuum furnace.
Claim 4
Dependent Claim
116 words
A process for annealing and quenching a workpiece in a furnace having an annealing chamber positioned above a quenching chamber and lateral heat insulation on the annealing chamber extending below the upper surface of the fluidized bed when said bed is not in its fluidized position, said quenching chamber having a fluidizable solid bed therein, said fluidizable bed when in the rest position serving as the bottom heat insulation for said annealing chamber, said process comprising flowing gas into said quenching chamber with a force sufficient to maintain the bed as a fluidized bed while said workpiece is in said bed and stopping the flow of said gas when the workpiece is inside said annealing chamber.
Claim 5
Dependent Claim
116 words
A process for annealing and quenching a workpiece in a furnace having an annealing chamber positioned above a quenching chamber and lateral heat insulation on the annealing chamber extending below the upper surface of the fluidized bed when said bed is not in its fluidized position, said quenching chamber having a fluidizable solid bed therein, said fluidizable bed when in the rest position serving as the bottom heat insulation for said annealing chamber, said process comprising flowing gas into said quenching chamber with a force sufficient to maintain the bed as a fluidized bed while said workpiece is in said bed and stopping the flow of said gas when the workpiece is inside said annealing chamber.
References Cited (Backward Citations)
US3197328A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1979-12-21 | 1980-06-21 | 1980-12-21 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1983-12-21 | 1984-06-21 | 1984-12-21 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1987-12-21 | 1988-06-21 | 1988-12-21 | $7700.00 | Window Closed / Lapsed |