US3744314A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Fuel gauges
Assignee: Individual
•
Filing: 1971-01-27
•
Granted: 1973-07-10
•
Expires: 1991-01-27
Abstract
Abstract Two coaxial tubes serving as plates of a capacitor to sense level of liquid. The level of liquid between the tubes being in proportion to the liquid level to be sensed. A circuit is provided responsive to the capacitance between the tubes including apparatus to vary the gain of an amplifier of the circuit to be lower at lower levels of the liquid.
Inventors
- 👤 C Lenny
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 10:06
CPC Classifications
G; G01; G01F; G01F23/00; G01F23/22; G01F23/26; G01F23/263
Claims Analysis
Total Claims: 3
Claim 1
Independent Claim
192 words
In a device which responds to the level of a liquid: a. a first tube which is adapted to be used as one plate of a capacitor and which first tube supports a second tube as a second plate of said capacitor, the tubes having a space therebetween which is partially filled by said liquid in proportion to said level, said liquid being a dielectric in said space; b. circuit means which is responsive to the value of said capacitor and which produces a first signal which is representative of said level of said liquid; c. a differential amplifier having two inputs one of which is said first signal, and having an output which is a function of said two inputs; d. driver means for driving a meter, said driver means being responsive to said output of said differential amplifier and also providing a third signal which determines the other of said inputs of said differential amplifier; and e. limiting means connected to said driver means to make the gain of said differential amplifier and the said driver means variable in order to reduce the gain at lower levels of said liquid.
Claim 2
Dependent Claim
192 words
In a device which responds to the level of a liquid: a. a first tube which is adapted to be used as one plate of a capacitor and which first tube supports a second tube as a second plate of said capacitor, the tubes having a space therebetween which is partially filled by said liquid in proportion to said level, said liquid being a dielectric in said space; b. circuit means which is responsive to the value of said capacitor and which produces a first signal which is representative of said level of said liquid; c. a differential amplifier having two inputs one of which is said first signal, and having an output which is a function of said two inputs; d. driver means for driving a meter, said driver means being responsive to said output of said differential amplifier and also providing a third signal which determines the other of said inputs of said differential amplifier; and e. limiting means connected to said driver means to make the gain of said differential amplifier and the said driver means variable in order to reduce the gain at lower levels of said liquid.
Claim 3
Dependent Claim
26 words
The device of claim 1 including indicator means wherein there is provided means controlled by said third signal to switch on and off said indicator means.
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) | 1976-07-09 | 1977-01-08 | 1977-07-10 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-07-09 | 1981-01-08 | 1981-07-10 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-07-09 | 1985-01-08 | 1985-07-10 | $7700.00 | Window Closed / Lapsed |