US4038011A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Apparatus for forming ribbed tubing
Assignee: Individual
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Filing: 1975-01-28
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Granted: 1977-07-26
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Expires: 1995-01-28
Abstract
Abstract An apparatus and method are provided for forming tubing by extrusion of a plastic or metal in an extrusion die over a mandrel supported within the die opening, and immediately after the tubing leaves the die but is still supported by the mandrel, operating thereon to provide a plurality of circular formations in the outer surface of the tubing for improving the physical characteristics of the tubing wall. In one form, the circular formations are provided by means of two or more reciprocating tools which engage and compress the freshly formed tubing against the mandrel, in an intermittent manner so as to form circular corrugations or thread-like formations in the outer stratum of the tube wall while the inside surface of the tube is maintained substantially in the configuration of the mandrel over which it is formed.
Inventors
- 👤 Jerome H. Lemelson
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 18:39
CPC Classifications
B; B29; B29C; B29C48/00; B29C48/25; B29C48/30; B29C48/32; B29C48/325; B29C48/03; B29C48/13; B29C48/001; B29C48/0022; B29C48/09; B29L; B29L2023/00; B29L2023/003
Claims Analysis
Total Claims: 4
Claim 1
Independent Claim
212 words
An apparatus for forming a tubular extrusion having a smooth inside wall surface and an irregular external wall surface comprising: first means for extruding a plastic material in the shape of a tube, said first means including an extrusion die and a stationary mandrel extending through said die for forming the inside surface of a tubular extrusion formed in said die, said mandrel having an end portion protruding a distance outwardly from said die, second means including tooling located externally of said die, said tooling including a pair of forming dies each having at least one semi-circular rib-like formation, said forming dies being operable to engage the tubular extrusion formed in said die against the end portion of said mandrel immediately after said extrusion has exited from said die, third means connected to said tooling for powering operating said tooling in synchronization with the movement of the extrusion from said die to cause said tooling to intermittently engage and disengage said tubing against said mandrel and to (predeterminately) deform a portion of the outer stratum of the extrusion as the extrusion passes over said mandrel so as to mold a plurality of circumferentially extending circular rib-like formations around said wall of said extrusion for varying the physical characteristics of said tubular extrusions.
Claim 2
Independent Claim
212 words
An apparatus for forming a tubular extrusion having a smooth inside wall surface and an irregular external wall surface comprising: first means for extruding a plastic material in the shape of a tube, said first means including an extrusion die and a stationary mandrel extending through said die for forming the inside surface of a tubular extrusion formed in said die, said mandrel having an end portion protruding a distance outwardly from said die, second means including tooling located externally of said die, said tooling including a pair of forming dies each having at least one semi-circular rib-like formation, said forming dies being operable to engage the tubular extrusion formed in said die against the end portion of said mandrel immediately after said extrusion has exited from said die, third means connected to said tooling for powering operating said tooling in synchronization with the movement of the extrusion from said die to cause said tooling to intermittently engage and disengage said tubing against said mandrel and to (predeterminately) deform a portion of the outer stratum of the extrusion as the extrusion passes over said mandrel so as to mold a plurality of circumferentially extending circular rib-like formations around said wall of said extrusion for varying the physical characteristics of said tubular extrusions.
Claim 3
Dependent Claim
77 words
An apparatus in accordance with claim 1 wherein said second means include a plurality of tube wall forming dies disposed around said end portion of said mandrel and each containing a plurality of semi-circular rib-like formations protruding therefrom which dies are operable to engage the outer stratum of the tubing extruded from said extrusion die as said tubing is supported by said mandrel and form a plurality of semi-circular rib-like formations in the wall of said tubing.
Claim 4
Dependent Claim
93 words
An apparatus in accordance with claim 2 wherein said plurality of forming dies comprise at least two die elements supported for movement toward and away from opposite wall portions of the tubular extrusion at it moves along said end portion of said mandrel and means operatively associated with said dies for reciprocably moving said forming dies toward and away from said extrusion so that each of said dies forms a plurality of rib-like formations in the outer stratum of the extrusion which said dies engage each time they are moved toward the extrusion.
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) | 1980-07-25 | 1981-01-24 | 1981-07-26 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1984-07-25 | 1985-01-24 | 1985-07-26 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1988-07-25 | 1989-01-24 | 1989-07-26 | $7700.00 | Window Closed / Lapsed |