US5473930A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Acceleration sensor with oppositely-polarized piezoelectric plates
Assignee: Robert Bosch GmbH
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Filing: 1995-02-06
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Granted: 1995-12-12
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Expires: 2015-02-06
Abstract
Abstract An acceleration sensor, which is particularly adapted for use in motor vehicles, is improved by structuring it to be readily testable, to assure reliability before installation. The acceleration sensor has a piezo element (1), which consists of at least two piezo-electric plates (2) placed on top of each other, the piezo-electrical polarization of which is oriented in opposite directions. At least two electrodes (9) are placed on each of the topside (7) and the underside (8) of the piezo element (1). For testing the sensor, the piezo element is deformed by the application of an electrical voltage to electrodes (9) of a first lateral portion (11a) of the piezo element. This deformation is detected by means of a deformation-generated voltage at the electrodes (9) of a second lateral portion (11b) of the piezo element.
Inventors
- 👤 Lothar Gademann
- 👤 Ulrich Kippelt
- 👤 Bernd Maihoefer
- 👤 Botho Ziegenbein
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-04 17:31
CPC Classifications
G; G01; G01P; G01P21/00; G01P15/00; G01P15/02; G01P15/08; G01P15/09; G01P15/0922
Claims Analysis
Total Claims: 13
Claim 1
Independent Claim
150 words
A testable acceleration sensor comprising a base (3); at least one piezoelectric element (1), mounted on said base (3), and formed as a sandwich structure of at least two piezoelectric plates (2) superposed on each other and having respective opposite polarizations, and an intermediate solid layer (10) mechanically interconnecting said plates; and at least two electrodes (9) applied to each of first and second lateral portions (11a, 11b) of said piezoelectric element; wherein, said lateral portions (11a, 11b) are electrically isolated from each other by an air gap (13) but are mechanically coupled to each other by a mechanical bridging means (12); and the sensor is testable by applying an electrical voltage to electrodes on said second lateral portion (11b), thereby causing a bending deformation of said element (1), said bending deformation giving rise to a test signal which is detectable at electrodes (9) on said first lateral portion (11a).
Claim 2
Dependent Claim
150 words
A testable acceleration sensor comprising a base (3); at least one piezoelectric element (1), mounted on said base (3), and formed as a sandwich structure of at least two piezoelectric plates (2) superposed on each other and having respective opposite polarizations, and an intermediate solid layer (10) mechanically interconnecting said plates; and at least two electrodes (9) applied to each of first and second lateral portions (11a, 11b) of said piezoelectric element; wherein, said lateral portions (11a, 11b) are electrically isolated from each other by an air gap (13) but are mechanically coupled to each other by a mechanical bridging means (12); and the sensor is testable by applying an electrical voltage to electrodes on said second lateral portion (11b), thereby causing a bending deformation of said element (1), said bending deformation giving rise to a test signal which is detectable at electrodes (9) on said first lateral portion (11a).
Claim 3
Dependent Claim
43 words
A testable acceleration sensor according to claim 1, wherein the piezo-electric element (1) has at least two electrodes (9) each, on an upper surface (7) and on a lower surface (8) thereof, and the electrodes (9) are arranged in pairs opposite each other.
Claim 4
Dependent Claim
41 words
A testable sensor according to claim 1, wherein said intermediate layer comprises a region of conductive adhesive (10) applied between said plates (2) in each of said first and second lateral element portions, said regions being electrically isolated from each other.
Claim 5
Dependent Claim
20 words
A sensor according to claim 3, wherein said regions are electrically isolated from each other by said air gap (13).
Claim 6
Dependent Claim
15 words
A sensor according to claim 1, wherein said mechanical bridging means is a ceramic bar.
Claim 7
Dependent Claim
16 words
A sensor according to claim 1, wherein said mechanical bridging means is a hardened adhesive droplet.
Claim 8
Dependent Claim
31 words
A sensor according to claim 2, wherein the shapes of the electrodes on said upper surface (7) and the shapes of the electrodes on said lower surface (8) are the same.
Claim 9
Dependent Claim
19 words
A sensor according to claim 2, wherein said intermediate layer (10) between said superposed plates (2) is electrically conductive.
Claim 10
Dependent Claim
18 words
A sensor according to claim 8, wherein said conductive intermediate layer (10) is shaped like said electrodes (9).
Claim 11
Dependent Claim
21 words
A sensor according to claim 1, wherein said intermediate layer includes an insulating layer between said plates (2) of said sensor.
Claim 12
Dependent Claim
18 words
A sensor according to claim 2, further comprising an insulating layer between said plates (2) of said sensor.
Claim 13
Dependent Claim
21 words
A sensor according to claim 7, wherein said intermediate layer includes an insulating layer between said plates (2) of said sensor.
References Cited (Backward Citations)
US3120622A
Cited
US3479536A
Cited
US3739202A
Cited
US4326143A
Cited
GB2117115A
Cited
US4621530A
Cited
US4532450A
Cited
US4661835A
Cited
DE3542397A1
Cited
DE3817354A1
Cited
US5063782A
Cited
DE3736394A1
Cited
US4996878A
Cited
EP0351038A1
Cited
US5083466A
Cited
DE3843143A1
Cited
US5178012A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1998-12-11 | 1999-06-12 | 1999-12-12 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2002-12-11 | 2003-06-12 | 2003-12-12 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2006-12-11 | 2007-06-12 | 2007-12-12 | $7700.00 | Window Closed / Lapsed |