US3790336A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method and apparatus for sintering annular compacts
Assignee: Motor Wheel Corp
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Filing: 1972-11-24
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Granted: 1974-02-05
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Expires: 1992-11-24
Abstract
Abstract A method and apparatus for sintering annular compacts without any substantial temperature gradients through the compacts. The method involves axial movement of the compact through vertical heating and cooling towers of a controlled atmosphere furnace with lateral movement of the compact through a crossover conduit interconnecting the upper ends of the towers. The lower end of the heating tower is provided with an inlet opening in constant communication with the exterior of the furnace and the lower end of the cooling tower has an outlet connected via a sealable exit chamber with the exterior of the furnace.
Inventors
- 👤 E Tuttle
- 👤 A Brede
- 👤 C Talmage
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 13:13
CPC Classifications
C; C21; C21D; C21D1/00; C21D1/74; B; B22; B22F; B22F3/00; B22F3/003
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
284 words
A vertical furnace with a controlled atmosphere for heating and cooling workpieces comprising: a. a heating tower extending generally vertically with a vertical length many times the vertical height of one of the workpieces, said heating tower having an inlet for workpieces adjacent its lower end continuously open to, and in communication with, the exterior of the furnace; b. a cooling tower extending generally vertically with a vertical length many times the vertical height of one of the workpieces, said cooling tower being adjacent to, and generally parallel with, said heating tower with said towers being interconnected adjacent their upper ends, said cooling tower having an outlet for workpieces adjacent the lower end thereof; c. an atmosphere lock connected with said outlet of said cooling tower and having an outlet in communication with the exterior of the furnace for transferring workpieces from said cooling tower to the exterior of the furnace without permitting said cooling tower to directly communicate with the exterior of the furnace through said outlet of said cooling tower; d. means for supplying a controlled atmosphere of a combustible gas to the interior of said towers such that said controlled atmosphere flows downwardly through at least said heating tower to the inlet thereof; e. means for causing the controlled atmosphere to continuously burn in a flame front interface with outside air adjacent said inlet; and f. means for moving the workpieces through said flame front interface as each workpiece enters said heating tower so that the workpieces are washed or purged of contaminating gases entrained therein as they move into said heating tower and contaminating gases are prevented from entering said heating tower through said inlet by said flame front interface.
Claim 2
Dependent Claim
284 words
A vertical furnace with a controlled atmosphere for heating and cooling workpieces comprising: a. a heating tower extending generally vertically with a vertical length many times the vertical height of one of the workpieces, said heating tower having an inlet for workpieces adjacent its lower end continuously open to, and in communication with, the exterior of the furnace; b. a cooling tower extending generally vertically with a vertical length many times the vertical height of one of the workpieces, said cooling tower being adjacent to, and generally parallel with, said heating tower with said towers being interconnected adjacent their upper ends, said cooling tower having an outlet for workpieces adjacent the lower end thereof; c. an atmosphere lock connected with said outlet of said cooling tower and having an outlet in communication with the exterior of the furnace for transferring workpieces from said cooling tower to the exterior of the furnace without permitting said cooling tower to directly communicate with the exterior of the furnace through said outlet of said cooling tower; d. means for supplying a controlled atmosphere of a combustible gas to the interior of said towers such that said controlled atmosphere flows downwardly through at least said heating tower to the inlet thereof; e. means for causing the controlled atmosphere to continuously burn in a flame front interface with outside air adjacent said inlet; and f. means for moving the workpieces through said flame front interface as each workpiece enters said heating tower so that the workpieces are washed or purged of contaminating gases entrained therein as they move into said heating tower and contaminating gases are prevented from entering said heating tower through said inlet by said flame front interface.
Claim 3
Dependent Claim
56 words
The furnace of claim 1 wherein said inlet for workpieces and said flame front interface extend generally horizontally, each workpiece is moved generally vertically upwardly through said flame front interface and inlet for workpieces into said heating tower, and the contaminating gases are flushed generally downwardly out of said heating tower via the flame front interface.
Claim 4
Dependent Claim
11 words
The furnace of claim 1 wherein the controlled atmosphere comprises hydrogen.
Claim 5
Dependent Claim
144 words
The furnace of claim 1 wherein said heating tower has a cylindrical casing therein having a source of heat circumferentially disposed about the outer periphery of said casing, said source of heat providing a heating zone in said cylindrical casing extending generally vertically many times the vertical extent of one of the workpieces with a vertically extending temperature gradient in said heating zone such that the vertical temperature gradient in each workpiece passing generally vertically upwardly therethrough is reduced to a minimum while said heat source simultaneously maintains a substantially uniform temperature in said heating zone at all points on any given circular path concentric with, and in a plane perpendicular to, the vertical axis of each workpiece passing upwardly through said heating zone such that the circumferential temperature gradient in each workpiece passing generally vertically upwardly through said heating zone is substantially eliminated.
Claim 6
Dependent Claim
43 words
The furnace of claim 4 wherein said cooling tower has a cylindrical casing therein providing a cooling zone within sAid cooling tower such that as each workpiece is moved generally vertically downwardly through said cooling zone the temperature of the workpiece is decreased.
Claim 7
Dependent Claim
259 words
A furnace for heating and cooling annular workpieces comprising a generally vertically extending heating tower having an inlet for workpieces adjacent its lower end opening to the exterior of the furnace, a generally vertically extending cooling tower having an outlet for workpieces adjacent its lower end, said towers being adjacent to, and generally parallel with, each other and interconnected adjacent their upper ends, a source of heat providing a heating zone within said heating tower extending generally vertically with a vertical length many times the axial extent of one of the annular workpieces to provide a temperature condition in said heating zone during passage of the workpieces therethrough such that a vertically extending temperature gradient is maintained in said heating zone such that the axial temperature gradient in each annular workpiece is reduced to a minimum while passing through said heating zone, while simultaneously maintaining a uniform temperature at all points on any given circular path concentric with the axis of an annular workpiece passing therethrough and in a plane perpendicular to the axis thereof such that the circumferential temperature gradient in each annular workpiece passing upwardly through said heating zone is substantially eliminated, and means for elevating the annular workpieces upwardly through said heating zone with the axis of each annular workpiece disposed generally vertically with the annular workpieces superimposed over each other in a generally vertical row and downwardly through said cooling tower with their axes oriented generally vertically to thereby substantially decrease distortion of the workpieces due to the heating and cooling thereof in the furnace.
Claim 8
Dependent Claim
259 words
A furnace for heating and cooling annular workpieces comprising a generally vertically extending heating tower having an inlet for workpieces adjacent its lower end opening to the exterior of the furnace, a generally vertically extending cooling tower having an outlet for workpieces adjacent its lower end, said towers being adjacent to, and generally parallel with, each other and interconnected adjacent their upper ends, a source of heat providing a heating zone within said heating tower extending generally vertically with a vertical length many times the axial extent of one of the annular workpieces to provide a temperature condition in said heating zone during passage of the workpieces therethrough such that a vertically extending temperature gradient is maintained in said heating zone such that the axial temperature gradient in each annular workpiece is reduced to a minimum while passing through said heating zone, while simultaneously maintaining a uniform temperature at all points on any given circular path concentric with the axis of an annular workpiece passing therethrough and in a plane perpendicular to the axis thereof such that the circumferential temperature gradient in each annular workpiece passing upwardly through said heating zone is substantially eliminated, and means for elevating the annular workpieces upwardly through said heating zone with the axis of each annular workpiece disposed generally vertically with the annular workpieces superimposed over each other in a generally vertical row and downwardly through said cooling tower with their axes oriented generally vertically to thereby substantially decrease distortion of the workpieces due to the heating and cooling thereof in the furnace.
Claim 9
Dependent Claim
28 words
The furnace of claim 6 wherein said heating zone is defined by a cylindrical casing and said heat source is disposed about the outer periphery of said casing.
Claim 10
Dependent Claim
32 words
The furnace of claim 7 which also comprises a cylindrical casing defining a cooling zone in said cooling tower and said casings in said towers are interconnected adjacent the upper ends thereof.
Claim 11
Dependent Claim
82 words
The furnace of claim 6 wherein said inlet for workpieces of said heating tower is continuously open to the exterior of the furnace and also comprises an atmosphere lock connected with said outlet of said cooling tower and having an outlet communicating with the exterior of the furnace for transferring annular workpieces from said cooling tower to the exterior of the furnace without allowing said cooling tower to communicate with the exterior of said furnace through said outlet of said cooling tower.
Claim 12
Dependent Claim
111 words
The furnace of claim 9 which also comprises means for providing a controlled atmosphere of a combustible gas in said towers which flows generally downwardly through said heating tower toward said inlet thereof, means for causing the controlled atmosphere to continually burn in a flame front interface with outside air adjacent said inlet for workpieces, and means for moving each annular workpiece through said flame front interface into said heating tower, whereby each annular workpiece is washed or purged of contaminating gases entrained therein as it moves into said heating tower and contaminating gases are prevented from entering said heating zone through said inlet for workpieces by said flame front interface.
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) | 1977-02-04 | 1977-08-06 | 1978-02-05 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-02-04 | 1981-08-06 | 1982-02-05 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-02-04 | 1985-08-06 | 1986-02-05 | $7700.00 | Window Closed / Lapsed |