US3771371A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Accelerometer having a liquid proof mass
Assignee: Kearfott Guidance and Navigation Corp
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Filing: 1971-11-26
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Granted: 1973-11-13
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Expires: 1991-11-26
Abstract
Abstract An accelerometer is provided comprising, a housing having a longitudinal sensing axis, a proof mass disposed in the housing and displaceable relative thereto, pickoff means disposed adjacent the proof mass and connected to the housing for sensing displacement of the proof mass, and force means mounted on the housing and disposed adjacent the proof mass for returning the proof mass to its null position after such displacement, wherein the proof mass comprises, a non-wetting liquid, and a container which is floated by the liquid and which is arranged to contain the liquid within the housing.
Inventors
- 👤 W Albert
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 07:48
CPC Classifications
G; G01; G01P; G01P15/00; G01P15/02; G01P15/08; G01P15/13; G01P15/132
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
159 words
An accelerometer comprising, a housing having a longitudinal sensing axis, a proof mass disposed in said housing and displaceable relative thereto, pickoff means mounted on said housing and disposed adjacent said proof mass for sensing the displacement of said proof mass, and force means mounted on said housing and disposed adjacent said proof mass for returning the proof mass to its null position after such displacement, wherein said proof mass comprises, a non-wetting liquid, and a container floated by said liquid and arranged to contain said liquid within said housing, said container including a pair of axially spaced discs disposed in bearing against said liquid, and a connector device, wherein said connector device includes, an elongate rod received in said cylinder and fixedly connected at one end thereof to the other of said discs, and tension spring means disposed between said discs, said tension spring means having opposite end portions connecting to said discs in bearing against said liquid.
Claim 2
Dependent Claim
159 words
An accelerometer comprising, a housing having a longitudinal sensing axis, a proof mass disposed in said housing and displaceable relative thereto, pickoff means mounted on said housing and disposed adjacent said proof mass for sensing the displacement of said proof mass, and force means mounted on said housing and disposed adjacent said proof mass for returning the proof mass to its null position after such displacement, wherein said proof mass comprises, a non-wetting liquid, and a container floated by said liquid and arranged to contain said liquid within said housing, said container including a pair of axially spaced discs disposed in bearing against said liquid, and a connector device, wherein said connector device includes, an elongate rod received in said cylinder and fixedly connected at one end thereof to the other of said discs, and tension spring means disposed between said discs, said tension spring means having opposite end portions connecting to said discs in bearing against said liquid.
Claim 3
Dependent Claim
89 words
The accelerometer as claimed in claim 1, wherein said housing includes, a peripheral wall and a pair of axially spaced end walls enclosing a cavity, said cavity being adapted to receive said proof mass, said peripheral wall having an elongate passage, said cavity having a first end portion disposed on one side of said proof mass and connecting to one end of said passage, said cavity having an opposite end portion disposed on the oppOsite side of said proof mass and connecting to an opposite end of said passage.
Claim 4
Dependent Claim
49 words
The accelerometer as claimed in claim 2, including an inert gas disposed in said first cavity portion and said second cavity portion and said interconnecting passage, said inert gas having a pressure which is substantially lower than the pressure being substantially different than the ambient pressure outside said housing.
Claim 5
Dependent Claim
59 words
The accelerometer as claimed in claim 3, wherein said pickoff means includes a pair of capacitor plates cooperating with one of said discs for sensing axial displacement of said proof mass relative to said housing, said capacitor plates having respective terminals embedded in said housing end wall adjacent hereto and projecting from said wall for connection to exterior conductors.
Claim 6
Dependent Claim
107 words
The accelerometer as claimed in claim 4, wherein said force means includes a magnet fixedly mounted on one of said housing end walls, a return path member fixedly mounted on said magnet for providing a flux field, and a force coil fixedly mounted on one of said proof mass discs, said return path member being disposed radially inwardly of said housing peripheral wall forming a cylindrical air gap therebetween, through which said flux field extends said force coil being disposed in said air gap for sensing said flux field, said force coil having terminals embedded in said housing wall and projecting therefrom for connection to exterior conductors.
Claim 7
Dependent Claim
29 words
The accelerometer as claimed in claim 5, including a servo system having conductors respectively connecting to said pickoff terminals and having conductors respectively connecting to said force coil terminals.
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) | 1976-11-12 | 1977-05-14 | 1977-11-13 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-11-12 | 1981-05-14 | 1981-11-13 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-11-12 | 1985-05-14 | 1985-11-13 | $7700.00 | Window Closed / Lapsed |