US3228075A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method for producing seamless pipe
Assignee: Th Calow and Co
•
Filing: 1963-03-19
•
Granted: 1966-01-11
•
Expires: 1983-03-19
Abstract
No abstract record available.
Inventors
- 👤 Lindemann Hans
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 15:28
CPC Classifications
B; B22; B22D; B22D11/00; B22D11/006; B21; B21C; B21C23/00; B21C23/02; B21C23/04; B21C23/08; B21C23/085; B21C29/00
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
167 words
AN EXTRUSION METHOD COMPRISING, IN COMBINATION, THE STEPS OF HEATING A MATERIAL AT LOW PRESSURE TO A HIGH TEMPERATURE AT WHICH THE MATERIAL IS IN THE LIQUID STATE, SAID MATERIAL BEING OF SUCH A NATURE AS TO SOLIDIFY AT SAID LOW PRESSURE AND AT A LOWER TEMPERATURE; REDUCING THE TEMPERATURE OF THE MATERIAL IN A CLOSED CONTAINER TO A SELECTED LOWER TEMPERATURE WHILE SIMULTANEOUSLY INCREASING THE PRESSURE IN THE CONTAINER; ADJUSTING THE PRESSURE IN THE CONTAINER TO A PREDETERMINED PRESSURE AT WHICH THE MATERIAL IS ADAPTED TO FLOW AT SAID SELECTED TEMPERATURE, BUT WHICH PREDETERMINED PRESSURE IS SELECTED SO THAT EVEN A SMALL REDUCTION OF SAID PREDETERMINED PRESSURE TO A SLIGHTLY REDUCED PRESSURE WOULD CAUSE THE MATERIAL TO SOLIDIFY AT SAID SELECTED TEMPERATURE; AND DISCHARGING THE MATERIAL AT SAID PREDETERMINED PRESSURE AND SELECTED TEMPERATURE FROM SAID CONTAINER THROUGH AN EXTRUSION NOZZLE INTO A SPACE HAVING A PRESSURE SUBSTANTIALLY LOWER THAN SAID SLIGHTLY REDUCED PRESSURE SO THAT THE DISCHARGED MATERIAL MOMENTARILY SOLIDIFIES DUE TO THE SUBSTANTIAL PRESSURE REDUCTION.
Claim 2
Dependent Claim
167 words
AN EXTRUSION METHOD COMPRISING, IN COMBINATION, THE STEPS OF HEATING A MATERIAL AT LOW PRESSURE TO A HIGH TEMPERATURE AT WHICH THE MATERIAL IS IN THE LIQUID STATE, SAID MATERIAL BEING OF SUCH A NATURE AS TO SOLIDIFY AT SAID LOW PRESSURE AND AT A LOWER TEMPERATURE; REDUCING THE TEMPERATURE OF THE MATERIAL IN A CLOSED CONTAINER TO A SELECTED LOWER TEMPERATURE WHILE SIMULTANEOUSLY INCREASING THE PRESSURE IN THE CONTAINER; ADJUSTING THE PRESSURE IN THE CONTAINER TO A PREDETERMINED PRESSURE AT WHICH THE MATERIAL IS ADAPTED TO FLOW AT SAID SELECTED TEMPERATURE, BUT WHICH PREDETERMINED PRESSURE IS SELECTED SO THAT EVEN A SMALL REDUCTION OF SAID PREDETERMINED PRESSURE TO A SLIGHTLY REDUCED PRESSURE WOULD CAUSE THE MATERIAL TO SOLIDIFY AT SAID SELECTED TEMPERATURE; AND DISCHARGING THE MATERIAL AT SAID PREDETERMINED PRESSURE AND SELECTED TEMPERATURE FROM SAID CONTAINER THROUGH AN EXTRUSION NOZZLE INTO A SPACE HAVING A PRESSURE SUBSTANTIALLY LOWER THAN SAID SLIGHTLY REDUCED PRESSURE SO THAT THE DISCHARGED MATERIAL MOMENTARILY SOLIDIFIES DUE TO THE SUBSTANTIAL PRESSURE REDUCTION.
References Cited (Backward Citations)
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1969-01-10 | 1969-07-12 | 1970-01-11 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1973-01-10 | 1973-07-12 | 1974-01-11 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1977-01-10 | 1977-07-12 | 1978-01-11 | $7700.00 | Window Closed / Lapsed |