US5629243A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Preloaded linear beam vibration sensor and its manufacturing method
Assignee: Tokyo Gas Co Ltd
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Filing: 1995-09-14
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Granted: 1997-05-13
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Expires: 2015-09-14
Abstract
Abstract A method is described for manufacturing a miniaturized accelerometer having a narrow bandwidth and behaving as a switch sensitive only to low frequencies such as are contained in earthquakes. The method includes provision of an unbalanced see-saw beam assembly composed of beams 2 and masses 3 at opposite ends of the beams 2. The beams 2 have their suspension at a location with slightly different distances from the masses 3 along a line parallel to and vertically offset from the line connecting centers of gravity of the masses 3.
Inventors
- 👤 Sean S. Cahill
- 👤 Walter Shoeys
- 👤 Kenichi Nakamura
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-07 18:32
CPC Classifications
G; G01; G01P; G01P15/00; G01P15/02; G01P15/08; G01P15/135; G01P15/0802; G01P2015/0805; G01P2015/0808; G01P2015/0811; G01P2015/0814; G01P2015/0822; G01P2015/0825; G01P2015/0831
Claims Analysis
Total Claims: 4
Claim 1
Independent Claim
161 words
A method for manufacturing a preloaded linear beam vibration sensor including an unbalanced see-saw type see-saw beam having its suspension at an intermediate portion thereof and a mass at each end thereof, comprising the steps of: providing a substrate; depositing on said substrate an oxide film; integrally making on said substrate, via a polysilcon film deposited on said oxide film, a see-saw beam comprising two parallel beams, two masses connecting said beams at respective ends and hinge posts extending from said beams at a location spaced different distances from said masses; depositing an oxide film on said see-saw beam; forming on said oxide film covering said hinge posts, via a polysilcon film, hinges which cover said hinge posts; etching part of said substrate underlying said see-saw beam to form a space permitting pivotal movement of said see-saw beam; and removing said oxide film covering said see-saw beam and said hinge posts to allow said beam to move freely within said hinges.
Claim 2
Independent Claim
161 words
A method for manufacturing a preloaded linear beam vibration sensor including an unbalanced see-saw type see-saw beam having its suspension at an intermediate portion thereof and a mass at each end thereof, comprising the steps of: providing a substrate; depositing on said substrate an oxide film; integrally making on said substrate, via a polysilcon film deposited on said oxide film, a see-saw beam comprising two parallel beams, two masses connecting said beams at respective ends and hinge posts extending from said beams at a location spaced different distances from said masses; depositing an oxide film on said see-saw beam; forming on said oxide film covering said hinge posts, via a polysilcon film, hinges which cover said hinge posts; etching part of said substrate underlying said see-saw beam to form a space permitting pivotal movement of said see-saw beam; and removing said oxide film covering said see-saw beam and said hinge posts to allow said beam to move freely within said hinges.
Claim 3
Independent Claim
174 words
A method for manufacturing a preloaded linear beam vibration sensor including an unbalanced see-saw type see-saw beam having its suspension at an intermediate portion thereof and a mass at each end thereof, comprising the steps of: providing a substrate; depositing on said substrate an oxide film; integrally making on said substrate, via a polysilicon film deposited on said oxide film, a see-saw beam comprising, two parallel beams, two masses connecting said beams at respective ends and hinge posts extending from said beams at a location spaced different distances from said masses; depositing an oxide film on said see-saw beam; forming on said oxide film, via a polysilicon film, hinges which cover said hinge posts; providing a lubricant layer of silicon nitride (SiN x ) between said hinge posts and said hinges; etching part of said substrate underlying said see-saw beam to form a space permitting pivotal movement of said see-saw beam; and removing said oxide film covering said see-saw beam and said hinge posts to allow said beam to move freely within said hinges.
Claim 4
Independent Claim
174 words
A method for manufacturing a preloaded linear beam vibration sensor including an unbalanced see-saw type see-saw beam having its suspension at an intermediate portion thereof and a mass at each end thereof, comprising the steps of: providing a substrate; depositing on said substrate an oxide film; integrally making on said substrate, via a polysilicon film deposited on said oxide film, a see-saw beam comprising, two parallel beams, two masses connecting said beams at respective ends and hinge posts extending from said beams at a location spaced different distances from said masses; depositing an oxide film on said see-saw beam; forming on said oxide film, via a polysilicon film, hinges which cover said hinge posts; providing a lubricant layer of silicon nitride (SiN x ) between said hinge posts and said hinges; etching part of said substrate underlying said see-saw beam to form a space permitting pivotal movement of said see-saw beam; and removing said oxide film covering said see-saw beam and said hinge posts to allow said beam to move freely within said hinges.
References Cited (Backward Citations)
US4736629A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 2000-05-12 | 2000-11-11 | 2001-05-13 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2004-05-12 | 2004-11-11 | 2005-05-13 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2008-05-12 | 2008-11-11 | 2009-05-13 | $7700.00 | Window Closed / Lapsed |