US3890685A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method for manufacturing hollow screws for heat exchangers
Assignee: Bayer AG
•
Filing: 1974-05-30
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Granted: 1975-06-24
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Expires: 1994-05-30
Abstract
Abstract Hollow screws for heat exchangers are produced by cutting a groove along the screw comb and by welding the edges of the groove walls to form a continuous void designed to communicate with inlets and outlets at the end of the screw.
Inventors
- 👤 Helmut Runte
- 👤 Peter Schwartz
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 11:34
CPC Classifications
F; F28; F28F; F28F5/00; F28F5/06; B; B23; B23P; B23P15/00; B23P15/26; Y; Y10; Y10T; Y10T29/00; Y10T29/49; Y10T29/49316
Claims Analysis
Total Claims: 5
Claim 1
Independent Claim
35 words
A method for manufacturing hollow screws for heat exchangers, comprising cutting a groove into the screw thread along the screw comb, and joining the edges of the groove walls together by an impervious weld seam.
Claim 2
Independent Claim
35 words
A method for manufacturing hollow screws for heat exchangers, comprising cutting a groove into the screw thread along the screw comb, and joining the edges of the groove walls together by an impervious weld seam.
Claim 3
Dependent Claim
17 words
A method as claimed in claim 1, wherein the groove is covered by a profile before welding.
Claim 4
Dependent Claim
13 words
A method as claimed in claim 1, wherein the weld seam is machine-finished.
Claim 5
Dependent Claim
13 words
A method as claimed in claim 2, wherein the weld seam is machine-finished.
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) | 1978-06-23 | 1978-12-23 | 1979-06-24 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-06-23 | 1982-12-23 | 1983-06-24 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-06-23 | 1986-12-23 | 1987-06-24 | $7700.00 | Window Closed / Lapsed |