US4906496A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Double-walled tube assembly
Assignee: SMC Corp
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Filing: 1987-10-14
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Granted: 1990-03-06
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Expires: 2007-10-14
Abstract
Abstract A double-walled tube assembly has an elongate inner tube of thermoplastic resin, and an elongate extruded outer tube of thermoplastic resin including a plurality of ribs having a constant height longitudinally of the outer tube and extending over the entire length of the outer tube, the ribs projecting toward the center of the outer tube. The ribs have distal ends fused to the outer perpiheral surface of the inner tube over the entire length of the inner and outer tubes. The rib width is from 0.5 to 1.5 mm. To continuously manufacture the double-walled tube assembly, the pre-molded inner tube is fed to an extrusion molding machine having a cross-head die, and thermoplastic resin is extruded from the cross-head die into an elongate outer tube around the inner tube. The inner tube and the extruded outer tube are fed into a sizing die device, in which the outer tube in a softened state is contracted toward the outer peripheral surface of the inner tube until the distal ends of the ribs of the outer tube are fused to the outer peripheral surface of the inner tube.
Inventors
- 👤 Masayuki Hosono
- 👤 Kenji Waragai
- 👤 Hirozo Uejo
- 👤 Mitsuru Tokumoto
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 19:11
CPC Classifications
F; F16; F16L; F16L37/00; F16L37/08; F16L37/084; F16L37/091; B; B29; B29C; B29C48/00; B29C48/03; B29C48/09; B29C48/11; B29C48/12; B29C48/15; B29C48/151; B29C48/25; B29C48/30; B29C48/32; B29C48/34; B29C48/88; B29C48/90; B29C48/901; B29C48/903; B29C48/911; B29C48/9115; F16L39/00; F16L9/00; F16L9/18; B29C48/885; B29C48/904; B29C48/908; B29C48/912; B29L; B29L2024/00; B29L2031/00; B29L2031/60; Y; Y10; Y10T; Y10T428/00; Y10T428/13; Y10T428/1352; Y10T428/139; Y10T428/24; Y10T428/24744
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
117 words
A double-walled tube assembly comprising: an elongate inner tube of thermoplastic resin; an elongate extruded outer tube of thermoplastic resin including a plurality of ribs having a constant height longitudinally of the outer tube and extending over the entire length of the outer tube, said ribs projecting from the inner wall surface of the outer tube toward the center of said outer tube; and said ribs having distal ends fused to the outer peripheral surface of said inner tube over the entire length of said inner and outer tubes; wherein said ribs range from 2 to 4 in number and each rib has a substantially constant width in the range of from about 0.1 to 1.5 mm.
Claim 2
Dependent Claim
117 words
A double-walled tube assembly comprising: an elongate inner tube of thermoplastic resin; an elongate extruded outer tube of thermoplastic resin including a plurality of ribs having a constant height longitudinally of the outer tube and extending over the entire length of the outer tube, said ribs projecting from the inner wall surface of the outer tube toward the center of said outer tube; and said ribs having distal ends fused to the outer peripheral surface of said inner tube over the entire length of said inner and outer tubes; wherein said ribs range from 2 to 4 in number and each rib has a substantially constant width in the range of from about 0.1 to 1.5 mm.
Claim 3
Dependent Claim
32 words
A double-walled tube assembly according to claim 1, wherein said outer and inner tubes are concentric with each other, said outer tube having an outside diameter ranging from 3 to 20 mm.
Claim 4
Dependent Claim
32 words
A double-walled tube assembly according to claim 1, wherein said outer and inner tubes are concentric with each other, said outer tube having a wall thickness ranging from 0.1 to 2 mm.
Claim 5
Dependent Claim
37 words
A double-walled tube assembly according to claim 1, wherein said outer and inner tubes are concentric with each other, said inner tube having an outside diameter which is 0.2 to 0.9 times that of said outer tube.
Claim 6
Dependent Claim
32 words
A double-walled tube assembly according to claim 1, wherein said outer and inner tubes are concentric with each other, said inner tube having a wall thickness ranging from 0.05 to 2 mm.
Claim 7
Dependent Claim
45 words
A double-walled tube assembly according to claim 1, wherein said outer and inner tubes are concentric with each other, said distal ends of said ribs being spaced from the inner wall surface of said outer tube by a distance ranging from 0.4 to 8 mm.
Claim 8
Dependent Claim
23 words
A double-walled tube assembly according to claim 2, wherein said outer tube has an outside diameter ranging from about 4 to 15 mm.
Claim 9
Dependent Claim
22 words
A double-walled tube assembly according to claim 3, wherein said outer tube has a wall thickness ranging from 0.2 to 1.5 mm.
Claim 10
Dependent Claim
28 words
A double-walled tube assembly according to claim 4, wherein said inner tube has an outside diameter which is about 0.4 to 0.8 times that of said outer tube.
Claim 11
Dependent Claim
23 words
A double-walled tube assembly according to claim 5, wherein said inner tube has a wall thickness ranging from about 0.1 to 1.5 mm.
Claim 12
Dependent Claim
18 words
A double-walled tube assembly according to claim 6, wherein said distance ranges from about 0.5 to 6 mm.
References Cited (Backward Citations)
US4157194A
Cited
JPS62113984A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1993-03-05 | 1993-09-04 | 1994-03-06 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1997-03-05 | 1997-09-04 | 1998-03-06 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2001-03-05 | 2001-09-04 | 2002-03-06 | $7700.00 | Window Closed / Lapsed |