Patent US3671695A successfully refreshed from Google Patents.
US3671695A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Brake fluid level sensor
Assignee: Motors Liquidation Co
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Filing: 1970-04-24
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Granted: 1972-06-20
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Expires: 1990-04-24
Abstract
Abstract A switch for use in a low fluid surface level warning system. A sealed diaphragm follows the varying fluid surface level. A string-like pull member whose one end is fixed to the diaphragm has its other end fixed to the free end of a leaf spring member of concavo-convex cross-section and of greater rigidity near its fixed end than its free end. Near the free end of the leaf spring member is an electrically conducting tongue extending toward the fixed end. As the liquid surface falls the string-like pull member forces the leaf spring member to bend near its free end until it snaps through and projects the tongue against another contact to complete an actuating circuit for a warning device.
Inventors
- 👤 Douglas J Wing
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 13:42
CPC Classifications
G; G01; G01F; G01F23/00; G01F23/14; G01F23/18; G01F23/185; G01F23/30; H; H01; H01H; H01H35/00; H01H35/18; H01H9/00; H01H9/02; H01H9/04; H01H2009/048
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
204 words
A switch for completing a current path through a circuit that includes a power source and an indicator device when fluid in a reservoir falls below a certain level comprising, in combination, a support; a fixed contact mounted on said support and connected in series with said circuit; a leaf spring that is connected in series with said circuit and has an end fixed to the support and a free end; and means mechanically coupled to the free end and responsive to the fluid level, the leaf spring having a tongue secured to its free end so as to extend substantially toward its fixed end, the leaf spring being curved in cross section and having at least one side crimped near the fixed end whereby the rigidity of the leaf spring is greater near the fixed end than at the free end, loading forces applied to the free end of the spring due to the fluid falling below the certain level thereby flexing the spring with a snap action due to the curved cross section so as to extend the tongue into electrical engagement with the fixed contact to complete the current path so long as the fluid level remains below the certain level.
Claim 2
Dependent Claim
204 words
A switch for completing a current path through a circuit that includes a power source and an indicator device when fluid in a reservoir falls below a certain level comprising, in combination, a support; a fixed contact mounted on said support and connected in series with said circuit; a leaf spring that is connected in series with said circuit and has an end fixed to the support and a free end; and means mechanically coupled to the free end and responsive to the fluid level, the leaf spring having a tongue secured to its free end so as to extend substantially toward its fixed end, the leaf spring being curved in cross section and having at least one side crimped near the fixed end whereby the rigidity of the leaf spring is greater near the fixed end than at the free end, loading forces applied to the free end of the spring due to the fluid falling below the certain level thereby flexing the spring with a snap action due to the curved cross section so as to extend the tongue into electrical engagement with the fixed contact to complete the current path so long as the fluid level remains below the certain level.
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) | 1975-06-20 | 1975-12-20 | 1976-06-20 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-06-20 | 1979-12-20 | 1980-06-20 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-06-20 | 1983-12-20 | 1984-06-20 | $7700.00 | Window Closed / Lapsed |