US3750444A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method of continuous production of tubing with helical or annular ribs
Assignee: KM Kabelmetal AG
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Filing: 1971-10-13
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Granted: 1973-08-07
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Expires: 1991-10-13
Abstract
Abstract Method of continuous production of ribbed tubes using a smoothwalled tube, corrugating same, and axially squeezing hollow corrugation crests of the tube, preferably by means of revolving die rollers, so that the interior surface portions of the sides of the crests as facing each other axially are folded and squeezed into surface to surface contact, to obtain integral ribs.
Inventors
- 👤 H Bittner
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 04:38
CPC Classifications
B; B21; B21D; B21D15/00; B21D15/04; Y; Y10; Y10T; Y10T29/00; Y10T29/49; Y10T29/4935; Y10T29/49377; Y10T29/49378; Y10T29/49382
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
89 words
Method of continuous production of ribbed tubes, comprising the steps of: providing a smooth-walled tube; corrugating said tube; axially squeezing hollow corrugation crests of the corrugated tubes in steps so that the interior surface portions of the sides of the crests as facing each other axially are folded and squeezed into surface-to-surface contact, to obtain integral ribs; and providing for straight wall configuration between the ribs, so that the wall surface of the tube between the ribs as well as the wall surface opposite the ribs is substantially smooth.
Claim 2
Dependent Claim
89 words
Method of continuous production of ribbed tubes, comprising the steps of: providing a smooth-walled tube; corrugating said tube; axially squeezing hollow corrugation crests of the corrugated tubes in steps so that the interior surface portions of the sides of the crests as facing each other axially are folded and squeezed into surface-to-surface contact, to obtain integral ribs; and providing for straight wall configuration between the ribs, so that the wall surface of the tube between the ribs as well as the wall surface opposite the ribs is substantially smooth.
Claim 3
Dependent Claim
31 words
Method as in claim 1, using die rollers for axially squeezing the crests, the rollers revolving about the axis of the tube, while maintaining the tube wall straight between the crests.
Claim 4
Dependent Claim
18 words
Method as in claim 2, using plural pairs of die rollers for progressively and stepwise squeezing the crests.
Claim 5
Dependent Claim
32 words
Method as in claim 3, one pair of rollers included in the plural pairs, having rollers with operating surface portions axially apart by about twice the wall thickness of the tube squeezed.
Claim 6
Dependent Claim
31 words
Method as in claim 3, wherein the pairs of rollers revolve about the tubes axis apart from each other by an angle of 120* from one pair to the next one.
Claim 7
Dependent Claim
30 words
Method as in claim 1, wherein the squeezing is obtained by advancing the corrugated tubing axially at different speeds, acting on different locations, so that in-between the corrugation is upset.
References Cited (Backward Citations)
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US1982369A
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US1963057A
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US2023417A
Cited
US2365515A
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US3353389A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1976-08-06 | 1977-02-05 | 1977-08-07 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-08-06 | 1981-02-05 | 1981-08-07 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-08-06 | 1985-02-05 | 1985-08-07 | $7700.00 | Window Closed / Lapsed |