Patent US3794794A successfully refreshed from Google Patents.
US3794794A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Impact responsive switch with frangible element holding contact plunger in unactivated position
Assignee: Ford Motor Co
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Filing: 1972-11-10
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Granted: 1974-02-26
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Expires: 1992-11-10
Abstract
Abstract The impact switch is responsive to the movement of a vehicle member subjected to an impact force as the result of a vehicle collision with a fixed object or another vehicle. The switch comprises a plunger device movable longitudinally within the cylindrical housing containing axially spaced electrically conductive contact rings. The plunger device carries an electrically conductive contact means engagable with the contact rings in sequence as the plunger device is driven into the housing. A shear pin normally holds the plunger device against displacement such as could be caused by vibration or longitudinally exerted inertial forces. Upon a predetermined impact force being applied to the plunger device, the shear pin is adapted to shear and permit displacement of the plunger means. Engagement of the plunger contact means with the contact rings closes an electrical circuit through the switch. The closed electrical circuit may be used to trigger an airbag system or other vehicle passenger restraint device.
Inventors
- 👤 R Provancher
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-04 17:58
CPC Classifications
B; B60; B60R; B60R21/00; B60R21/01; B60R21/013; B60R21/0136; H; H01; H01H; H01H13/00; H01H13/02; H01H35/00; H01H35/14; H01H35/146
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
129 words
An impact responsive switch comprising a cylindrical housing, electrically conductive contact means longitudinally axially spaced within the housing, the axially spaced contact means comprising a pair of rings having radially inwardly projecting contact fingers, plunger means slidably journalled at one end of the housing for longitudinal displacement movement therein, the plunger means comprising an anvil the inner end of which projects into the housing, a nonconductive connector member carried on the anvil inner end, and electrically conductive contact member coupled to the connector member, the electrically conductive contact member being of sufficient length to bridge the axially spaced contact means upon impact induced axial displacement of the plunger means into the cylindrical housing, and shear pin means holding the plunger means against displacement movement below a predetermined impact force.
Claim 2
Dependent Claim
129 words
An impact responsive switch comprising a cylindrical housing, electrically conductive contact means longitudinally axially spaced within the housing, the axially spaced contact means comprising a pair of rings having radially inwardly projecting contact fingers, plunger means slidably journalled at one end of the housing for longitudinal displacement movement therein, the plunger means comprising an anvil the inner end of which projects into the housing, a nonconductive connector member carried on the anvil inner end, and electrically conductive contact member coupled to the connector member, the electrically conductive contact member being of sufficient length to bridge the axially spaced contact means upon impact induced axial displacement of the plunger means into the cylindrical housing, and shear pin means holding the plunger means against displacement movement below a predetermined impact force.
Claim 3
Dependent Claim
23 words
An impact responsive switch according to claim 1, in which: the shear pin means couples the plunger means anvil to the cylindrical housing.
Claim 4
Dependent Claim
32 words
An impact responsive switch according to claim 2, in which: the axially spaced electrically conductive contact means are axially spaced from each other by a plurality of axially positioned nonconductive spacer rings.
Claim 5
Dependent Claim
35 words
An impact responsive switch according to claim 3, in which: the axially spaced electrically conductive means are spaced from the inner wall of the cylindrical housing by a nonconductive ring concentric with the spacer rings.
Claim 6
Dependent Claim
30 words
An impact responsive switch according to claim 1, in which: the axially spaced contact means rings are axially positioned within the cylindrical housing by a plurality of nonconductive spacer rings.
Claim 7
Dependent Claim
36 words
An impact responsive switch according to claim 5, in which: the contact means rings are positioned in nonconductive relationship to the inner wall of the cylindrical housing by a nonconductive ring concentric with the spacer rings.
References Cited (Backward Citations)
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US3217121A
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US3286064A
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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) | 1977-02-25 | 1977-08-27 | 1978-02-26 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-02-25 | 1981-08-27 | 1982-02-26 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-02-25 | 1985-08-27 | 1986-02-26 | $7700.00 | Window Closed / Lapsed |