Patent US3662333A successfully refreshed from Google Patents.
US3662333A
Expired / Lapsed
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Hydraulic accumulator charge detector and indicating system
Assignee: Bendix Corp
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Filing: 1970-09-08
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Granted: 1972-05-09
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Expires: 1990-09-08
Abstract
Abstract In a hydraulic braking system, a means for determining if the charge on an accumulator is low. A pressure sensitive transistor gives an output that is proportional to the pressure in the accumulator. When the brake switch is closed, the output of the pressure sensitive transistor is memorized. After a given time period, if the actual pressure in the accumulator has dropped a predetermined amount below the memorized pressure, an output will light a warning indicator lamp. A latching arrangement will keep the light on even if the pressure later increases and the brake pedal is released.
Inventors
- 👤 Donald W Howard
- 👤 Dewey W Eppley
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 06:53
CPC Classifications
B; B60; B60T; B60T8/00; B60T8/17; B60T8/172; B60T17/00; B60T17/18; B60T17/22
Claims Analysis
Total Claims: 13
Claim 1
Independent Claim
97 words
A pressure indicating system, comprising: transducer means for giving a voltage signal proportional to a pressure input; means for memorizing said voltage signal when a command signal is received; means for comparing said memorized voltage signal with the existing voltage signal from said transducer means to give a signal output when the existing voltage signal has changed a predetermined amount with reference to said memorized voltage signal; and means for gating said signal output from said comparing means to give an indication if said signal output occurred within a predetermined period of time after said command signal.
Claim 2
Dependent Claim
97 words
A pressure indicating system, comprising: transducer means for giving a voltage signal proportional to a pressure input; means for memorizing said voltage signal when a command signal is received; means for comparing said memorized voltage signal with the existing voltage signal from said transducer means to give a signal output when the existing voltage signal has changed a predetermined amount with reference to said memorized voltage signal; and means for gating said signal output from said comparing means to give an indication if said signal output occurred within a predetermined period of time after said command signal.
Claim 3
Dependent Claim
22 words
The pressure indicating system, as recited in claim 1, wherein said predetermined amount of change indicates a decrease in said pressure input.
Claim 4
Dependent Claim
47 words
The pressure indicating system, as recited in claim 2, wherein said gating means includes a timer means activated by said command signal and a gate that gives an indication voltage output if an input is received from said timer and said signal output from said comparing means.
Claim 5
Dependent Claim
40 words
The pressure indicating system, as recited in claim 2, wherein said indication is provided by means which includes an indicator lamp and latch means operated when said output signal is received through said gating means to maintain a warning indication.
Claim 6
Dependent Claim
48 words
The pressure indicating system, as recited in claim 3, wherein: said pressure input is received from a pressure accumulator of a braking system; and said command signal is a voltage from a brake switch in said braking system, said brake switch being closed when the brakes are applied.
Claim 7
Dependent Claim
119 words
In a hydraulic braking system having a pressurized fluid accumulator, an accumulator pressure indicator system comprising: a source of pressurized fluid; a housing for said accumulator, said housing being connected to said source of predetermined fluid; diaphragm means for dividing said housing into a first and second chamber, said first chamber receiving said pressurized fluid and said second chamber containing a pressurized gas; transducer means connected to one of said first and second chambers for giving a voltage proportional to the pressure in said chamber; means for determining changes in said proportional voltage for a unit of time, said predetermining means giving an output if said change exceeds a predetermined amount; and means for indicating if said output exists.
Claim 8
Dependent Claim
119 words
In a hydraulic braking system having a pressurized fluid accumulator, an accumulator pressure indicator system comprising: a source of pressurized fluid; a housing for said accumulator, said housing being connected to said source of predetermined fluid; diaphragm means for dividing said housing into a first and second chamber, said first chamber receiving said pressurized fluid and said second chamber containing a pressurized gas; transducer means connected to one of said first and second chambers for giving a voltage proportional to the pressure in said chamber; means for determining changes in said proportional voltage for a unit of time, said predetermining means giving an output if said change exceeds a predetermined amount; and means for indicating if said output exists.
Claim 9
Dependent Claim
65 words
The accumulator pressure indicator system, as recited in claim 6, wherein said determining means includes: means for memorizing said proportional voltage upon receiving a command from a brake switch means; and means for comparing said memorized proportional voltage with the actual proportional voltage so that, if the actual proportional voltage had decreased said predetermined amount in said unit of time, said output will be obtained.
Claim 10
Dependent Claim
67 words
The accumulator pressure indicating system, as recited in claim 6, wherein said determining means includes: means for taking the derivative of said proportional voltage; and means for comparing said derivative with a reference, said reference representing a change in said proportional voltage for said unit of time as said unit of time approaches zero, said comparing means giving said output if said reference change has been exceeded.
Claim 11
Dependent Claim
19 words
The accumulator pressure indicator system, as recited in claim 7, wherein said transducer means is a pressure responsive transistor.
Claim 12
Dependent Claim
21 words
The accumulator pressure indicator system, as recited in claim 9, wherein said indicating means includes an indicator lamp and latch means.
Claim 13
Dependent Claim
20 words
The accumulator pressure indicator system, as recited in claim 10, wherein said latch means includes a relay with appropriate contacts.
References Cited (Backward Citations)
US3511088A
Cited
US3573725A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1975-05-09 | 1975-11-08 | 1976-05-09 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-05-09 | 1979-11-08 | 1980-05-09 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-05-09 | 1983-11-08 | 1984-05-09 | $7700.00 | Window Closed / Lapsed |