US4256686A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method and device for the production of an oxide ceramic tube
Assignee: W HALDENWANGER KG A CORP OF GERMANY
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Filing: 1978-03-22
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Granted: 1981-03-17
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Expires: 1998-03-22
Abstract
Abstract A device and a method for producing a closed end tube with the tube wall and the end being thereof one continuous piece. The tube is made in a repeatable process in such a way that the tube possesses uniform strength in all areas.
Inventors
- 👤 Leonhard E. Froschauer
- 👤 Rudolf U. B. Knape
- 👤 Dieter H. Schmidt
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 05:37
CPC Classifications
B; B28; B28B; B28B21/00; B28B21/52; B28B3/00; B28B3/20; B28B3/26; B28B3/2627
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
143 words
A method for the production of an oxide ceramic tube which is completely closed at one end by a continuous process comprising the steps of: extruding plasticized oxide ceramic material through a screen and over a spike; closing a die having a hemisphere shape for forming the end; increasing a space associated with the die as the extrusion process continues which space is connected with the die cavity by means of a first venting hole; after complete formation of the closed end, moving the die downward and sideways to clear the tube; opening a second venting hole in the spike by retraction of a needle for the admission of air into the inside of the tube; and continuing extrusion of the tube to a desired length with the admission of air to the inside of the tube to prevent collapse of the tube.
Claim 2
Independent Claim
143 words
A method for the production of an oxide ceramic tube which is completely closed at one end by a continuous process comprising the steps of: extruding plasticized oxide ceramic material through a screen and over a spike; closing a die having a hemisphere shape for forming the end; increasing a space associated with the die as the extrusion process continues which space is connected with the die cavity by means of a first venting hole; after complete formation of the closed end, moving the die downward and sideways to clear the tube; opening a second venting hole in the spike by retraction of a needle for the admission of air into the inside of the tube; and continuing extrusion of the tube to a desired length with the admission of air to the inside of the tube to prevent collapse of the tube.
References Cited (Backward Citations)
US3879507A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1984-03-16 | 1984-09-15 | 1985-03-17 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1988-03-16 | 1988-09-15 | 1989-03-17 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1992-03-16 | 1992-09-15 | 1993-03-17 | $7700.00 | Window Closed / Lapsed |