US4142581A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Tube-hole structure for expanded tube-to-tube-sheet joint
Assignee: Hitachi Ltd
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Filing: 1977-03-30
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Granted: 1979-03-06
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Expires: 1997-03-30
Abstract
Abstract A tube-hole structure for an expanded tube-to-tube-sheet joint which is formed by axially moving a rod within each tube member in each tube hole of the tube sheet by external drive means, thereby imparting an elastic mass placed inside the tube with a sufficient compressive load to expand the tube uniformly in the radial direction to provide a rigid joint between the tube and tube hole, characterized in that each tube hole has at least one circumferential groove with an axial dimension or length of 1.5/ beta to 3.0/ beta ( beta being <IMAGE> WHERE R is the mean radius of the tube member to be expanded, t is the wall thickness of the tube, and nu is the Poisson's ratio).
Inventors
- 👤 Yuji Yoshitomi
- 👤 Zensuke Tamura
- 👤 Hideaki Kamohara
- 👤 Keiji Omura
- 👤 Yoshimasa Murakami
- 👤 Tadasi Takata
- 👤 Teruo Nuwa
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 16:29
CPC Classifications
B; B21; B21D; B21D39/00; B21D39/06; F; F28; F28F; F28F9/00; F28F9/02; F28F9/04; F28F9/16; Y; Y10; Y10S; Y10S165/00; Y10S165/454; Y10S165/492; Y10S165/494; Y10T; Y10T29/00; Y10T29/49; Y10T29/4935; Y10T29/49373; Y10T29/49375; Y10T29/49826; Y10T29/49908; Y10T29/49938; Y10T29/4994
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
94 words
A tube-hole structure for an expanded tube-to-tube-sheet joint wherein at least one circumferential groove is formed on the surrounding wall of each tube hole of a sheet into which each tube member is inserted and uniformly expanded to provide a joint, characterized in that the axial dimension of each said groove is in the range from about 1.5/β to about 3.0/β (β being calculated from ##EQU7## wherein R is the mean radius of the tube member to be expanded, t is the wall thickness of the tube member, and ν is the Poisson's ratio).
Claim 2
Dependent Claim
94 words
A tube-hole structure for an expanded tube-to-tube-sheet joint wherein at least one circumferential groove is formed on the surrounding wall of each tube hole of a sheet into which each tube member is inserted and uniformly expanded to provide a joint, characterized in that the axial dimension of each said groove is in the range from about 1.5/β to about 3.0/β (β being calculated from ##EQU7## wherein R is the mean radius of the tube member to be expanded, t is the wall thickness of the tube member, and ν is the Poisson's ratio).
Claim 3
Dependent Claim
33 words
The tube-hole structure of claim 1, characterized in that said tube member is radially outwardly and uniformly expanded by means of a tube-expanding medium of elastic material disposed inside of said tube member.
Claim 4
Dependent Claim
21 words
The tube-hole structure of claim 1, characterized in that two grooves are formed near both ends of each said tube hole.
Claim 5
Dependent Claim
21 words
The tube-hole structure of claim 1, characterized in that the depth of each said groove is not less than 0.4 mm.
Claim 6
Independent Claim
112 words
A method of manufacturing a tube-hole structure for an expanded tube-to-tube-sheet joint comprising the steps of: a. forming at least one circumferential groove on a surrounding wall of each tube hole of a tube sheet, wherein the axial dimension of each said groove is in the range from about 1.5/β to about 3.0/β (β being calculated from ##EQU8## wherein R is the mean radius of a tube member to be expanded, t is the wall thickness of the tube member, and ν is Poisson's ratio; b. inserting one tube member into each tube hole of the tube sheet; and c. expanding said tube member into said circumferential groove to provide a joint.
Claim 7
Independent Claim
112 words
A method of manufacturing a tube-hole structure for an expanded tube-to-tube-sheet joint comprising the steps of: a. forming at least one circumferential groove on a surrounding wall of each tube hole of a tube sheet, wherein the axial dimension of each said groove is in the range from about 1.5/β to about 3.0/β (β being calculated from ##EQU8## wherein R is the mean radius of a tube member to be expanded, t is the wall thickness of the tube member, and ν is Poisson's ratio; b. inserting one tube member into each tube hole of the tube sheet; and c. expanding said tube member into said circumferential groove to provide a joint.
Claim 8
Dependent Claim
38 words
The method of manufacturing the tube-hole structure according to claim 5, further comprising the step of disposing a tube-expanding medium means of elastic material inside of said tube member for radially outwardly and uniformly expanding said tube member.
Claim 9
Dependent Claim
27 words
The method of manufacturing the tube-hole structure according to claim 5, further comprising the step of forming two grooves near both ends of each said tube hole.
Claim 10
Dependent Claim
28 words
The method of manufacturing the tube-hole structure according to claim 5, further comprising the step of making the depth of each said groove not less than 0.4 mm.
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) | 1982-03-05 | 1982-09-04 | 1983-03-06 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1986-03-05 | 1986-09-04 | 1987-03-06 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1990-03-05 | 1990-09-04 | 1991-03-06 | $7700.00 | Window Closed / Lapsed |