US3782323A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Self contained fluidic level sensor
Assignee: Bowles Fluidics Corp
•
Filing: 1972-06-09
•
Granted: 1974-01-01
•
Expires: 1992-06-09
Abstract
Abstract A pressure pulse, selectively initiated from the dashboard of a motor vehicle, is applied to two compartments separated by a diaphragm. One compartment is vented and receives the pressure pulse via a sensor tube extending toward the diaphragm. The second compartment communicates with a dip tube extending to the sensing level in the vehicle oil reservoir. If the oil is above the dip tube, the diaphragm is flexed by the pressure pulse and blocks the sensor tube so that the pulse cannot be vented. The pulse is thus shunted to a pressure responsive indicator which provides a momentary indication that the oil level is above the sensing level. If the oil is below the dip tube, the pressure pulse is vented through the dip tube and sensor tube, rendering the indicator unactuated.
Inventors
- 👤 D Jones
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 14:46
CPC Classifications
G; G01; G01F; G01F23/00; G01F23/14; G01F23/16; G01F23/161; Y; Y10; Y10T; Y10T137/00; Y10T137/8158; Y10T137/8342
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
250 words
A liquid levEl sensor, comprising: a volume separated into first and second pressure-isolated chambers by a pressure-responsive flexible member; venting means for providing communication between said first chamber and ambient pressure; a sensor tube extending into said first chamber toward said flexible member such that said sensor tube is blocked when said flexible member is flexed into said first chamber and is unblocked when said flexible member is unflexed; a dip tube having a sensing end terminating at a predetermined level in a reservoir of liquid in which the level is to be sensed; initiator means for at will generating a pressure pulse; a pressure-responsive indicator for registering a first indication when unpressurized and a second indication when pressurized; a first fluid passage for applying said pressure pulse to said dip tube and said second chamber such that said second chamber is maintained at ambient pressure when the liquid level is below said sensing end of said dip tube, said second chamber becoming pressurized to flex said flexible member and block said sensor tube when the sensing end of said dip tube is blocked by said liquid level; and second fluid passage means for applying said pressure pulse to said sensor tube and said indicator such that said pressure pulse is vented via said first chamber and said indicator remains unpressurized when said sensor tube is unblocked by said flexible member, said pressure pulse actuating said indicator to provide said second indication when said flexible member blocks said sensor tube.
Claim 2
Dependent Claim
250 words
A liquid levEl sensor, comprising: a volume separated into first and second pressure-isolated chambers by a pressure-responsive flexible member; venting means for providing communication between said first chamber and ambient pressure; a sensor tube extending into said first chamber toward said flexible member such that said sensor tube is blocked when said flexible member is flexed into said first chamber and is unblocked when said flexible member is unflexed; a dip tube having a sensing end terminating at a predetermined level in a reservoir of liquid in which the level is to be sensed; initiator means for at will generating a pressure pulse; a pressure-responsive indicator for registering a first indication when unpressurized and a second indication when pressurized; a first fluid passage for applying said pressure pulse to said dip tube and said second chamber such that said second chamber is maintained at ambient pressure when the liquid level is below said sensing end of said dip tube, said second chamber becoming pressurized to flex said flexible member and block said sensor tube when the sensing end of said dip tube is blocked by said liquid level; and second fluid passage means for applying said pressure pulse to said sensor tube and said indicator such that said pressure pulse is vented via said first chamber and said indicator remains unpressurized when said sensor tube is unblocked by said flexible member, said pressure pulse actuating said indicator to provide said second indication when said flexible member blocks said sensor tube.
Claim 3
Dependent Claim
48 words
The liquid level sensor according to claim 1 employed in a motor vehicle having an engine and a passenger compartment, wherein said initiator means and said indicator are located in said passenger compartment and said dip tube extends into a reservoir containing a liquid employed in said engine.
Claim 4
Dependent Claim
36 words
The liquid level sensor according to claim 1 wherein said initiator means comprises a push button which is arranged to collapse a bellows when said button is depressed, said bellows, when collapsed, expelling said pressure pulse.
Claim 5
Dependent Claim
30 words
The liquid level sensor according to claim 1 wherein said initiator means comprises a compartment normally maintained at ambient pressure and manually operable to collapse and expel said pressure pulse.
Claim 6
Dependent Claim
47 words
The liquid level sensor according to claim 1 further comprising: a plurality of said dip tubes, each having a sensing end disposed at a respective level in a different liquid reservoir; selector means for manually connecting individual ones of said dip tubes to said first fluid passage.
Claim 7
Dependent Claim
50 words
The liquid level sensor according to claim 5 employed in a motor vehicle having a passenger compartment and an engine compartment, wherein said initiator means, said indicator and said selector means are located in said passenger compartment and said dip tubes are located in respective reservoirs in said engine compartment.
Claim 8
Dependent Claim
84 words
The liquid level sensor according to claim 1 wherein said initiator means comprises a hollow cylinder having forward and rearward ends, a piston mounted to translation longitudinally inside said cylinder, bias means for urging said piston toward said forward end of said cylinder, and manually operable means for momentarily translating said piston toward the rearward end of said cylinder, whereby said piston, upon release by said manually operable means, is urged toward and expels said pressure pulse from said forward end of said cylinder.
Claim 9
Independent Claim
75 words
The method of monitoring motor oil level in a motor vehicle, said method including the steps of: generating a pressure pulse from a location inside the passenger compartment of said vehicle; applying said pressure pulse to a dip tube having a sensor end disposed at a predetermined level in a reservoir for said motor oil; and actuating an indicator in said passenger compartment when the motor oil in said reservoir is above said predetermined level.
Claim 10
Independent Claim
75 words
The method of monitoring motor oil level in a motor vehicle, said method including the steps of: generating a pressure pulse from a location inside the passenger compartment of said vehicle; applying said pressure pulse to a dip tube having a sensor end disposed at a predetermined level in a reservoir for said motor oil; and actuating an indicator in said passenger compartment when the motor oil in said reservoir is above said predetermined level.
Claim 11
Dependent Claim
56 words
The method according to claiM 8 wherein the step of actuating comprises: applying said pressure pulse to a normally vented passage; blocking said normally vented passage when the sensor end of said dip tube is blocked by said motor oil; and re-directing said pressure pulse when said normally vented passage is blocked to actuate said indicator.
Claim 12
Dependent Claim
39 words
The method according to claim 9 further comprising the steps of: from a location inside said passenger compartment, selectively directing said pressure pulse to individual dip tubes having respective sensor ends located in respective liquid reservoirs in said vehicle.
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) | 1976-12-31 | 1977-07-02 | 1978-01-01 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-12-31 | 1981-07-02 | 1982-01-01 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-12-31 | 1985-07-02 | 1986-01-01 | $7700.00 | Window Closed / Lapsed |