Patent US3933488A successfully refreshed from Google Patents.
Patent US5044201A successfully refreshed from Google Patents.
US5044201A
Expired / Lapsed
US
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Double-integrating silicon acceleration sensing device
Assignee: Motorola Solutions Inc
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Filing: 1990-08-13
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Granted: 1991-09-03
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Expires: 2010-08-13
Abstract
Abstract A double integrating silicon acceleration sensing device which is solid state and micromachined measures the acceleration of an object and determines the distance travelled by that object through its trajectory. The device comprises a hermetically sealed container. The cavity within the container is divided by a flexible silicon diaphragm into two separate cavities, one shallow and the other deep. The two cavities are filled with a fluid which is relatively incompressible over the range of operating pressure. The fluid can only transfer between the two cavities through an orifice. Two capacitor plates form a capacitor within the shallow cavity. One of the plates is secured to a central portion of the diaphragm, and the other plate is secured adjacent to and opposite of the first plate within the shallow cavity. When the accelerometer is at rest, the two plates are separated by a given distance X g . When the accelerometer experiences an acceleration, the diaphragm deflects into the deep cavity forcing fluid from the deep cavity into the shallow cavity. The gap between the two capacitor plates X g increases causing a change in the total capacitance. This capacitance value is exactly proportional to the distance travelled by the object for constant acceleration, and is approximately proportional to the distance travelled for other acceleration pulses. When capacitor plates are coupled adjacent and opposite each other in the deep cavity, in addition to capacitor plates in the shallow cavity, a differential capacitance results.
Inventors
- 👤 Louis P. Farace
- 👤 John D. Titus
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-05 05:04
CPC Classifications
G; G01; G01P; G01P15/00; G01P15/02; G01P15/08; G01P15/125; G01P15/0802
Claims Analysis
Total Claims: 17
Claim 1
Independent Claim
119 words
An acceleration sensing device comprising: device housing including a sealed cavity; flexible diaphragm dividing said sealed cavity into a plurality of small cavities; said plurality of small cavities filled with a generally incompressible fluid; conduit means connecting said plurality of small cavities; said conduit means allowing flow of said fluid between said plurality of small cavities: a plurality of capacitor plates : a first of said plurality of capacitor plates coupled to said flexible diaphragm and a second of said plurality of capacitor plates coupled to said housing and adjacent to said first of said plurality of capacitor plates; and orifice means for controlling the rate of flow of said generally incompressible fluid between said plurality of small cavities.
Claim 2
Dependent Claim
119 words
An acceleration sensing device comprising: device housing including a sealed cavity; flexible diaphragm dividing said sealed cavity into a plurality of small cavities; said plurality of small cavities filled with a generally incompressible fluid; conduit means connecting said plurality of small cavities; said conduit means allowing flow of said fluid between said plurality of small cavities: a plurality of capacitor plates : a first of said plurality of capacitor plates coupled to said flexible diaphragm and a second of said plurality of capacitor plates coupled to said housing and adjacent to said first of said plurality of capacitor plates; and orifice means for controlling the rate of flow of said generally incompressible fluid between said plurality of small cavities.
Claim 3
Dependent Claim
42 words
An acceleration sensing device according to claim 1 wherein said flexible diaphragm comprises: a plurality of semi-spherical cavity means for increasing the flexibility of said diaphragm ; and said plurality of semi-spherical cavity means blemishing at least one face of said diaphragm.
Claim 4
Dependent Claim
29 words
An acceleration sensing device according to claim 2 wherein said plurality of semi-spherical cavity means are arranged in a hexagonal close pack pattern on said at least one face.
Claim 5
Dependent Claim
16 words
An acceleration sensing device according to claim 1 wherein said flexible diaphragm comprises a silicon material.
Claim 6
Dependent Claim
51 words
An acceleration sensing device according to claim 1 wherein said acceleration sensing device further comprises: a third of said plurality of capacitor plates coupled to said flexible diaphragm; and a fourth of said plurality of capacitor plates coupled to said housing adjacent to said third of said plurality of capacitor plates.
Claim 7
Dependent Claim
108 words
In a vehicle system, an acceleration sensing device comprising: silicon diaphragm; first means for increasing the flexibility of said silicon diaphragm, said first means coupled to said silicon diaphragm; said first means including: a plurality of semi-spherical cavity means for increasing the flexibility of said silicon diaphragm; said plurality of semi-sperical cavity means blemishing at least one face of said silicon diaphragm; said silicon diaphragm coupled across and dissecting a sealed chamber containing a fluid; second means for allowing said fluid to flow between the dissected portions of said sealed chamber at a predetermined rate; and said second means connected between the dissected portions of said sealed chamber.
Claim 8
Dependent Claim
108 words
In a vehicle system, an acceleration sensing device comprising: silicon diaphragm; first means for increasing the flexibility of said silicon diaphragm, said first means coupled to said silicon diaphragm; said first means including: a plurality of semi-spherical cavity means for increasing the flexibility of said silicon diaphragm; said plurality of semi-sperical cavity means blemishing at least one face of said silicon diaphragm; said silicon diaphragm coupled across and dissecting a sealed chamber containing a fluid; second means for allowing said fluid to flow between the dissected portions of said sealed chamber at a predetermined rate; and said second means connected between the dissected portions of said sealed chamber.
Claim 9
Dependent Claim
24 words
An acceleration sensing device according to claim 6 wherein said second means comprises an orifice for controlling the rate of flow of said fluid.
Claim 10
Dependent Claim
147 words
In a vehicle system, an acceleration sensing device comprising: device housing including a sealed cavity; flexible diaphragm dividing said sealed cavity into a plurality of small cavities; said plurality of small cavities filled with a generally incompressible fluid; a plurality of semi-spherical cavity means for increasing the flexibility of said diaphragm; said plurality of semi-spherical cavity means blemishing at least one face of said diaphragm; conduit means connecting said plurality of small cavities; said conduit allowing flow of said fluid between said plurality of small cavities; a plurality of capacitor plates; a first of said plurality of capacitor plates coupled to said flexible diaphragm; a second of said plurality of capacitor plates coupled to said housing and adjacent to said first of said plurality of capacitor plates; and orifice means for controlling the rate of flow of said generally incompressible fluid between said plurality of small cavities.
Claim 11
Dependent Claim
147 words
In a vehicle system, an acceleration sensing device comprising: device housing including a sealed cavity; flexible diaphragm dividing said sealed cavity into a plurality of small cavities; said plurality of small cavities filled with a generally incompressible fluid; a plurality of semi-spherical cavity means for increasing the flexibility of said diaphragm; said plurality of semi-spherical cavity means blemishing at least one face of said diaphragm; conduit means connecting said plurality of small cavities; said conduit allowing flow of said fluid between said plurality of small cavities; a plurality of capacitor plates; a first of said plurality of capacitor plates coupled to said flexible diaphragm; a second of said plurality of capacitor plates coupled to said housing and adjacent to said first of said plurality of capacitor plates; and orifice means for controlling the rate of flow of said generally incompressible fluid between said plurality of small cavities.
Claim 12
Dependent Claim
29 words
An acceleration sensing device according to claim 8 wherein said plurality of semi-spherical cavity means are arranged in a hexagonal close pack pattern on said at least one face.
Claim 13
Dependent Claim
16 words
An acceleration sensing device according to claim 8 wherein said flexible diaphragm comprises a silicon material.
Claim 14
Dependent Claim
49 words
An acceleration sensing device according to claim 8 wherein the device further comprises: a third of said plurality of capacitor plates coupled to said flexible diaphragm; and a fourth of said plurality of capacitor plates coupled to said housing adjacent to said third of said plurality of capacitor plates.
Claim 15
Dependent Claim
86 words
In a projectile system, an acceleration sensing device comprising: silicon diaphragm; a plurality of semi-spherical cavity means for increasing the flexibility of said silicon diaphragm; said plurality of semi-spherical cavity means blemishing at least one face of said silicon diaphragm; said silicon diaphragm coupled across and dissecting a sealed chamber containing a fluid; means for allowing said fluid to flow between the dissected portions of said sealed chamber at a predetermined rate; and said means for allowing connected between the dissected portions of said sealed chamber.
Claim 16
Dependent Claim
86 words
In a projectile system, an acceleration sensing device comprising: silicon diaphragm; a plurality of semi-spherical cavity means for increasing the flexibility of said silicon diaphragm; said plurality of semi-spherical cavity means blemishing at least one face of said silicon diaphragm; said silicon diaphragm coupled across and dissecting a sealed chamber containing a fluid; means for allowing said fluid to flow between the dissected portions of said sealed chamber at a predetermined rate; and said means for allowing connected between the dissected portions of said sealed chamber.
Claim 17
Dependent Claim
24 words
An acceleration sensing device according to claim 12 wherein said second means comprises an orifice for controlling the rate of flow of said fluid.
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) | 1994-09-02 | 1995-03-04 | 1995-09-03 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1998-09-02 | 1999-03-04 | 1999-09-03 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2002-09-02 | 2003-03-04 | 2003-09-03 | $7700.00 | Window Closed / Lapsed |