US3861206A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method and device for measuring a stress employing magnetostriction
Assignee: Hitachi Ltd
•
Filing: 1973-04-02
•
Granted: 1975-01-21
•
Expires: 1993-04-02
Abstract
Abstract A method of measuring a stress of a material to be measured comprising the steps of magnetizing a ferromagnetic film formed on the surface of the material and detecting the variation of a magnetic flux of the film which is dependent upon the variation of the stress of the material to be measured, and a device for putting the method into practice.
Inventors
- 👤 Kazuyoshi Kawafune
- 👤 Koji Nakazawa
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 16:22
CPC Classifications
G; G01; G01L; G01L3/00; G01L3/02; G01L3/04; G01L3/10; G01L3/101; G01L3/102; G01L1/00; G01L1/12; G01L1/125; G01L1/127; G01L3/103; G01L3/105; Y; Y10; Y10S; Y10S73/00; Y10S73/02
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
141 words
In a method for measuring stress in a material by measuring a variation of the magnetostriction is a magnetostrictive material in response to stress applied to the material to be stress measured, the improvement comprising: compensating for structural irregularities of the permeability of said magnetostrictive material by providing a film of a nonmagnetic substance on a surface of the material to be stress measured, by providing a film having magnetostrictive characteristics over said film of non-magnetic substance and by passing magnetic flux through the magnetostrictive film; and measuring the variation of magnetic flux in said magnetostrictive film in response to stress of said material to be stress measured, said improvement further comprising applying a predetermined magnetic field to said magnetostrictive film during the step of providing said magnetostrictive film over said non-magnetic film to effect magnetic anisotropy to said magnetostrictive film.
Claim 2
Dependent Claim
141 words
In a method for measuring stress in a material by measuring a variation of the magnetostriction is a magnetostrictive material in response to stress applied to the material to be stress measured, the improvement comprising: compensating for structural irregularities of the permeability of said magnetostrictive material by providing a film of a nonmagnetic substance on a surface of the material to be stress measured, by providing a film having magnetostrictive characteristics over said film of non-magnetic substance and by passing magnetic flux through the magnetostrictive film; and measuring the variation of magnetic flux in said magnetostrictive film in response to stress of said material to be stress measured, said improvement further comprising applying a predetermined magnetic field to said magnetostrictive film during the step of providing said magnetostrictive film over said non-magnetic film to effect magnetic anisotropy to said magnetostrictive film.
Claim 3
Dependent Claim
19 words
A method according to claim 1, wherein said magnetostrictive film covers a smaller surface area than said non-magnetic film.
Claim 4
Dependent Claim
40 words
A method according to claim 1, wherein said non-magnetic film is provided on said material to be stress measured at a predetermined thickness, said thickness being dependent on the degree of magnetic characteristics of said material to be stress measured.
Claim 5
Dependent Claim
21 words
A method according to claim 1, wherein only said magnetostrictive film imparts an influence on the measurement of magnetic flux variation.
Claim 6
Dependent Claim
17 words
A method according to claim 1, wherein said magnetostrictive film is uniformly provided over said non-magnetic film.
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) | 1978-01-20 | 1978-07-22 | 1979-01-21 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-01-20 | 1982-07-22 | 1983-01-21 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-01-20 | 1986-07-22 | 1987-01-21 | $7700.00 | Window Closed / Lapsed |