Patent US3976899A successfully refreshed from Google Patents.
US3976899A
Expired / Lapsed
US
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Snap action mechanical-electrical piezoelectric transducer
Assignee: US Philips Corp
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Filing: 1974-12-23
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Granted: 1976-08-24
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Expires: 1994-12-23
Abstract
Abstract A mechanical-electrical transducer producing an electric signal upon depression of a spring, such as a pushbutton. A piezoelectric element is held in contact with a snap-action spring, and bends when the spring snaps thus producing an electric signal.
Inventors
- 👤 David Geoffrey James Fanshawe
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 11:22
CPC Classifications
H; H01; H01H; H01H13/00; H01H13/70; H01H13/702; H03; H03K; H03K17/00; H03K17/94; H03K17/96; H03K17/964; H03K17/965; H03K17/967; H10; H10N; H10N30/00; H10N30/30; H01H2201/00; H01H2201/02; H01H2215/00; H01H2215/034; H01H2223/00; H01H2223/034; H01H2223/036; H01H2227/00; H01H2227/028; H01H2227/032; H03K2217/00; H03K2217/94; H03K2217/96; H03K2217/96015; H03K2217/96027
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
144 words
A mechanical-electrical transducer comprising a monostable snap action spring formed from a sheet of material of the type which snaps from a first shape to a second shape along one dimension upon application of at least a given force to the spring, and a piezoelectric element; in the absence of force applied to the spring, a portion of the spring extending transverse to said one dimension being bowed transverse to said dimension, said bow being substantially constant upon application of force less than said given force to the spring; upon said spring snapping along said one dimension, said bow changing to a transverse bow in an opposite direction; and piezoelectric means for sensing change of said direction of said transverse bow only, said means comprising said piezoelectric element and means for holding said piezoelectric element in contact with said transverse portion of said spring.
Claim 2
Dependent Claim
144 words
A mechanical-electrical transducer comprising a monostable snap action spring formed from a sheet of material of the type which snaps from a first shape to a second shape along one dimension upon application of at least a given force to the spring, and a piezoelectric element; in the absence of force applied to the spring, a portion of the spring extending transverse to said one dimension being bowed transverse to said dimension, said bow being substantially constant upon application of force less than said given force to the spring; upon said spring snapping along said one dimension, said bow changing to a transverse bow in an opposite direction; and piezoelectric means for sensing change of said direction of said transverse bow only, said means comprising said piezoelectric element and means for holding said piezoelectric element in contact with said transverse portion of said spring.
Claim 3
Dependent Claim
52 words
A transducer as claimed in claim 1, wherein said first dimension extends longitudinally of said sheet of material, said spring being symmetrical about a longitudinal plane, and adapted to snap upon application of said given force along a direction lying in said plane, said transverse portion being substantially perpendicular to said plane.
Claim 4
Dependent Claim
17 words
A transducer as claimed in claim 2, wherein said piezoelectric element is elongated in said transverse direction.
Claim 5
Dependent Claim
21 words
A transducer as claimed in claim 1, wherein said means for holding comprises a material bonding said element to said spring.
Claim 6
Dependent Claim
22 words
A transducer as claimed in claim 1, wherein said means for holding comprises a resilient clamping member extending transverse to said dimension.
Claim 7
Dependent Claim
90 words
A mechanical electrical transducer comprising a blade spring adapted for flexure along one dimension from a first position to a second position, said blade spring having a snap action at a point intermediate said two positions and having a portion bowed transversely to said dimension, the direction of said transverse bow reversing upon said snap action, a piezoelectric element, and means for holding said piezoelectric element in contact with said bowed portion, said piezoelectric element being responsive solely to reversal of the bow direction for generation of an output voltage.
Claim 8
Dependent Claim
90 words
A mechanical electrical transducer comprising a blade spring adapted for flexure along one dimension from a first position to a second position, said blade spring having a snap action at a point intermediate said two positions and having a portion bowed transversely to said dimension, the direction of said transverse bow reversing upon said snap action, a piezoelectric element, and means for holding said piezoelectric element in contact with said bowed portion, said piezoelectric element being responsive solely to reversal of the bow direction for generation of an output voltage.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1979-08-24 | 1980-02-23 | 1980-08-24 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1983-08-24 | 1984-02-23 | 1984-08-24 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1987-08-24 | 1988-02-23 | 1988-08-24 | $7700.00 | Window Closed / Lapsed |