Patent US3726835A successfully refreshed from Google Patents.
US4043014A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method of making a waste flue heat recovery device
Assignee: Individual
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Filing: 1975-11-11
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Granted: 1977-08-23
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Expires: 1995-11-11
Abstract
Abstract A novel and easy method of construction and assembly which enables a tubular coil to be inserted in an open flue pipe so the flue pipe can be joined; water passing through the coil will recover waste flue heat from furnaces and boilers.
Inventors
- 👤 John C. Wilson
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 20:56
CPC Classifications
F; F28; F28D; F28D21/00; F28D21/0001; F28D21/0003; F28D21/0005; F28D21/0007; F22; F22D; F22D1/00; F22D1/02; Y; Y10; Y10T; Y10T29/00; Y10T29/49; Y10T29/4935; Y10T29/49357
Claims Analysis
Total Claims: 4
Claim 1
Independent Claim
125 words
A method of manufacturing a heat recovery unit which consists of providing a flue pipe blank, forming a pair of Longitudinally aligned holes which are located at one end of said blank, forming a water heating coil by forming a plurality of coil turns, forming one end of the coil with a straight portion of tubing extending therefrom, forming the other end of the coil with a second straight portion that extends through the middle of the coil and then bending the second straight portion at the right angles to extend parallel to the first straight portion, inserting the ends of said portions through said aligned holes, wrapping the flue pipe blank around the coil and joining the edges of the flue pipe blank together.
Claim 2
Independent Claim
125 words
A method of manufacturing a heat recovery unit which consists of providing a flue pipe blank, forming a pair of Longitudinally aligned holes which are located at one end of said blank, forming a water heating coil by forming a plurality of coil turns, forming one end of the coil with a straight portion of tubing extending therefrom, forming the other end of the coil with a second straight portion that extends through the middle of the coil and then bending the second straight portion at the right angles to extend parallel to the first straight portion, inserting the ends of said portions through said aligned holes, wrapping the flue pipe blank around the coil and joining the edges of the flue pipe blank together.
Claim 3
Independent Claim
131 words
A method of manufacturing a heat recovery unit which consists of providing a flue pipe blank, forming a pair of longitudinally aligned holes which are located at opposite ends of said flue pipe blank, forming a water heating coil by forming a plurality of coil turns, forming one end of the coil with a straight portion of tubing extending therefrom, forming the other end of the coil with a second straight section of tubing which extends from the coil at right angles and in the same direction and parallel to the first straight section portion, inserting the ends of said portions through the aligned holes at opposite ends of said flue pipe blank, wrapping the flue pipe blank around the coil and joining the edges of the flue pipe blank together.
Claim 4
Independent Claim
131 words
A method of manufacturing a heat recovery unit which consists of providing a flue pipe blank, forming a pair of longitudinally aligned holes which are located at opposite ends of said flue pipe blank, forming a water heating coil by forming a plurality of coil turns, forming one end of the coil with a straight portion of tubing extending therefrom, forming the other end of the coil with a second straight section of tubing which extends from the coil at right angles and in the same direction and parallel to the first straight section portion, inserting the ends of said portions through the aligned holes at opposite ends of said flue pipe blank, wrapping the flue pipe blank around the coil and joining the edges of the flue pipe blank together.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1980-08-22 | 1981-02-21 | 1981-08-23 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1984-08-22 | 1985-02-21 | 1985-08-23 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1988-08-22 | 1989-02-21 | 1989-08-23 | $7700.00 | Window Closed / Lapsed |