US3789885A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Internally supported thin walled duct
Assignee: Individual
•
Filing: 1972-05-18
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Granted: 1974-02-05
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Expires: 1992-05-18
Abstract
Abstract A thin walled duct, operating at reduced pressure, is maintained rigid by an internal packing of particles that does not materially affect low velocity fluid flow through the duct.
Inventors
- 👤 J Wilson
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 10:40
CPC Classifications
F; F28; F28D; F28D9/00; F16; F16L; F16L9/00; F28F; F28F13/00; F28F13/003; Y; Y10; Y10T; Y10T428/00; Y10T428/25
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
73 words
A fluid carrier operating under reduced pressure comprising a thin walled duct having a wall thickness on the order of 2 to 20 mils and a plurality of particles packed in said duct to structurally rigidify the same and maintain a flow path through the duct, said particles being contiguously arranged within the duct to support the walls of the duct while not materially interfering with the flow of fluid through the duct.
Claim 2
Dependent Claim
73 words
A fluid carrier operating under reduced pressure comprising a thin walled duct having a wall thickness on the order of 2 to 20 mils and a plurality of particles packed in said duct to structurally rigidify the same and maintain a flow path through the duct, said particles being contiguously arranged within the duct to support the walls of the duct while not materially interfering with the flow of fluid through the duct.
Claim 3
Dependent Claim
19 words
The invention of claim 1 wherein said particles are not mechanically attached to the duct or to each other.
Claim 4
Dependent Claim
21 words
The invention of claim 1 wherein said duct has a preferred wall thickness on the order of 3 to 10 mils.
Claim 5
Dependent Claim
16 words
The invention of claim 1 wherein said contiguous particles are generally spheroidal and of uniform size.
Claim 6
Dependent Claim
16 words
The invention of claim 3 wherein said contiguous particles are generally in a square pitch pack.
Claim 7
Dependent Claim
16 words
The invention of claim 3 wherein said contiguous particles are generally in a triangular pitch pack.
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) | 1977-02-04 | 1977-08-06 | 1978-02-05 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-02-04 | 1981-08-06 | 1982-02-05 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-02-04 | 1985-08-06 | 1986-02-05 | $7700.00 | Window Closed / Lapsed |