US3634639A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Brake failure warning device with relatively movable detented contact bars actuatable by different pressure sources
Assignee: Bendix Corp
•
Filing: 1970-11-04
•
Granted: 1972-01-11
•
Expires: 1990-11-04
Abstract
Abstract A dual plunger differential pressure indicating device for use in a ground vehicle having separate hydraulic braking systems for the front and rear brakes thereof which will indicate the occurrence of a malfunction in either one of the hydraulic braking systems. The indicating device includes a detent latching device for maintaining the indicating device in an activated position and mechanism for hydraulically resetting the device after correction of the malfunction.
Inventors
- 👤 Howard R Jilbert
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 06:10
CPC Classifications
H; H01; H01H; H01H35/00; H01H35/24
Claims Analysis
Total Claims: 13
Claim 1
Independent Claim
166 words
In a fluid system having first and second sources of fluid pressure, a differential pressure indicating device comprising: a housing having first and second pressure-responsive means located therein, one of which is operatively connected to and moveably responsive to said first source of fluid pressure and the other of which is operatively connected to and movably responsive to said second source of fluid pressure; electrical switch means located in said housing and having a pair of contact bars, one of which is operatively connected to and movable with one of said pressure-responsive means and the other of which is operatively connected to and movable with the other of said pressure-responsive means; and detent means formed on said contact bars for activating a warning signal upon relative movement between said bars; said detent means moving from a nonlatching to a latching position upon relative movement of said bars to provide a continuous warning signal until predetermined pressures are subsequently applied to said first and second pressureresponsive means.
Claim 2
Dependent Claim
166 words
In a fluid system having first and second sources of fluid pressure, a differential pressure indicating device comprising: a housing having first and second pressure-responsive means located therein, one of which is operatively connected to and moveably responsive to said first source of fluid pressure and the other of which is operatively connected to and movably responsive to said second source of fluid pressure; electrical switch means located in said housing and having a pair of contact bars, one of which is operatively connected to and movable with one of said pressure-responsive means and the other of which is operatively connected to and movable with the other of said pressure-responsive means; and detent means formed on said contact bars for activating a warning signal upon relative movement between said bars; said detent means moving from a nonlatching to a latching position upon relative movement of said bars to provide a continuous warning signal until predetermined pressures are subsequently applied to said first and second pressureresponsive means.
Claim 3
Dependent Claim
113 words
A differential pressure indicating device, as defined in claim 1, wherein said housing includes first and second ports communicating respectively with said first and second sources of fluid pressure, first and second bores connected respectively to said first and second ports, and a cavity located intermediate said bores; said first and second pressure-responsive means includes first and second plungers respectively slidable in said first and second bores, one of said plungers being operatively connected to one of said contact bars to cause movement thereof and the other of said plungers being operatively connected to the other of said contact bars to cause movement thereof; and said contact bars are located in said cavity.
Claim 4
Dependent Claim
32 words
A differential pressure indicating device, as defined in claim 2, which includes lever means located between said plungers and said contact bars for transmitting motion from said plungers to said contact bars.
Claim 5
Dependent Claim
21 words
A differential pressure indicating device, as defined in claim 3, which includes first resilient means for opposing movement of said plungers.
Claim 6
Dependent Claim
20 words
A differential pressure indicating device, as defined in claim 4, wherein said first resilient means are located in said bores.
Claim 7
Dependent Claim
40 words
A differential pressure indicating deVice, as defined in claim 4, which includes electrical circuit means for activating said warning signal, wherein said first resilient means is located in said housing and is a component part of said electrical circuit means.
Claim 8
Dependent Claim
27 words
A differential pressure indicating device, as defined in claim 4, which includes second resilient means located in said cavity for urging said contact bars toward each other.
Claim 9
Dependent Claim
33 words
A differential pressure indicating device, as defined in claim 7, which includes electrical circuit means for activating said warning signal wherein said second resilient means is a component part of said electrical circuit.
Claim 10
Dependent Claim
63 words
A differential pressure indicating device, as defined in claim 8, which includes diaphragm means in contact with the ends of said first and second plungers and located between said first and second ports and said first and second plungers, respectively, to isolate said first and second sources of fluid pressure from said electrical switch means and prevent cross leakage between said pressure sources.
Claim 11
Dependent Claim
82 words
A differential pressure indicating device, as defined in claim 9, wherein said lever means includes a first lever located between said first plunger and one of said contact bars and a second lever located between said second plunger and the other of said contact bars, said first and second levers each having one end thereof pivotally connected to said housing, the other end thereof operatively connected to its associated contact bar, and an intermediate portion thereof operatively connected to its associated plunger.
Claim 12
Dependent Claim
82 words
A differential pressure indicating device, as defined in claim 9, wherein said lever means include a first lever located between said first plunger and one of said contact bars and a second lever located between said second plunger and the other of said contact bars, said first and second levers each having one end thereof operatively connected to its associated plunger, the other end thereof operatively connected to its associated contact bar, and an intermediate portion thereof pivotally connected to said housing.
Claim 13
Dependent Claim
23 words
A differential pressure warning switch, as defined in claim 11, wherein said lever means is a component part of said electrical circuit means.
References Cited (Backward Citations)
US2435143A
Cited
US2630499A
Cited
FR1120862A
Cited
US3011595A
Cited
US3314047A
Cited
US3228194A
Cited
US3382333A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1975-01-10 | 1975-07-12 | 1976-01-11 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-01-10 | 1979-07-12 | 1980-01-11 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-01-10 | 1983-07-12 | 1984-01-11 | $7700.00 | Window Closed / Lapsed |