Patent US4457059A successfully refreshed from Google Patents.
US4457059A
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US
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Method of making a re-entrant groove heat pipe
Assignee: Grumman Corp
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Filing: 1982-05-24
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Granted: 1984-07-03
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Expires: 2002-05-24
Abstract
Abstract A sealed heat pipe of uniform cross sectional profile from evaporator to condenser which includes a plurality of capillary channels communicating with a central channel by means of narrow re-entrant groove openings having convergent entrances. A two step method of fabrication includes extruding the re-entrant grooves, then drawing a mandrel through the virgin extrusion.
Inventors
- 👤 Joseph P. Alario
- 👤 Robert Kosson
- 👤 Edward Leszak
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 14:21
CPC Classifications
B; B21; B21C; B21C37/00; B21C37/06; B21C37/15; B21C37/20; B21C37/202; B21C37/151; F; F28; F28D; F28D15/00; F28D15/02; F28D15/04; Y; Y10; Y10T; Y10T29/00; Y10T29/49; Y10T29/4935; Y10T29/49353
Claims Analysis
Total Claims: 5
Claim 1
Independent Claim
197 words
A method for making a convergent, re-entrant groove heat pipe comprising: forming a desired length of seamless tube with a plurality of longitudinal capillary channels in a wall thereof and a like plurality of re-entrant groove openings each providing communication between an associated one of the capillary channels and a central channel of the tube, said capillary channels and associated re-entrant openings being defined by a like plurality of ribs each projecting inwardly toward the central channel of the tube and having a head portion closest to the central channel relatively thicker than a base portion thereof whereby the re-entrant openings are narrower than the capillary channels; aligning the tube with a mandrel having a plurality of spines shaped to correspond to a desired re-entrant groove entrance profile such that each spine is centered between adjacent ribs in one of the re-entrant groove openings; drawing the mandrel through the tube such that rib material on either side of each re-entrant groove opening is displaced while material from a central portion of each rib remains undisplaced, resulting in a convergent, re-entrant groove profile; sealing the tube at either end; and injecting the tube with a suitable working fluid.
Claim 2
Independent Claim
197 words
A method for making a convergent, re-entrant groove heat pipe comprising: forming a desired length of seamless tube with a plurality of longitudinal capillary channels in a wall thereof and a like plurality of re-entrant groove openings each providing communication between an associated one of the capillary channels and a central channel of the tube, said capillary channels and associated re-entrant openings being defined by a like plurality of ribs each projecting inwardly toward the central channel of the tube and having a head portion closest to the central channel relatively thicker than a base portion thereof whereby the re-entrant openings are narrower than the capillary channels; aligning the tube with a mandrel having a plurality of spines shaped to correspond to a desired re-entrant groove entrance profile such that each spine is centered between adjacent ribs in one of the re-entrant groove openings; drawing the mandrel through the tube such that rib material on either side of each re-entrant groove opening is displaced while material from a central portion of each rib remains undisplaced, resulting in a convergent, re-entrant groove profile; sealing the tube at either end; and injecting the tube with a suitable working fluid.
Claim 3
Dependent Claim
24 words
The method of claim 1 in which the spines are V-shaped and have an apex angle corresponding to a desired angle of convergent entrance.
Claim 4
Dependent Claim
37 words
The method of claim 1 in which the spines define a plurality of troughs, each trough having a radius of curvature which increases from a midpoint of the trough to a flat portion of the adjacent spines.
Claim 5
Dependent Claim
48 words
The method of claim 1 wherein the step of drawing the mandrel through the tube comprises: inserting a draw bar into the tube; attaching the mandrel to a first end of the draw bar; and forcing a second end of the draw bar axially away from the tube.
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) | 1987-07-03 | 1988-01-02 | 1988-07-03 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1991-07-03 | 1992-01-02 | 1992-07-03 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1995-07-03 | 1996-01-02 | 1996-07-03 | $7700.00 | Window Closed / Lapsed |