US3678490A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Master cylinder low fluid indicator
Assignee: Bendix Corp
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Filing: 1971-03-24
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Granted: 1972-07-18
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Expires: 1991-03-24
Abstract
Abstract A fluid level warning device for indicating to the driver that an abnormally low supply of fluid is available in the master cylinder reservoir for actuating the brakes of a vehicle. The device includes a horizontally disposed reed switch which is located in the wall of the reservoir and a magnet secured to the reservoir diaphragm for actuating the switch.
Inventors
- 👤 James Basil Putt
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-22 20:51
CPC Classifications
G; G01; G01F; G01F23/00; G01F23/30; G01F23/14; G01F23/18; G01F23/185
Claims Analysis
Total Claims: 4
Claim 1
Independent Claim
133 words
In a master cylinder: a wall defining fluid reservoir means therewithin; a cover member for closing said reservoir means; diaphragm means operatively connected between said wall and said cover member and adapted to follow the fluid level in said reservoir means; magnetically operated switch means located in said wall, said switch means having a pair of contacts movable from a nonactuated position to an actuated position; signal means for indicating a predetermined fluid level in said reservoir means; electrical circuit means operatively connecting said signal means with said switch means; and magnetic means fixedly connected to said diaphragm means for actuating said switch means when said diaphragm means moves near said switch means, said switch means being actuated upon movement of said pair of contacts from said non-actuated position to said actuated position.
Claim 2
Dependent Claim
133 words
In a master cylinder: a wall defining fluid reservoir means therewithin; a cover member for closing said reservoir means; diaphragm means operatively connected between said wall and said cover member and adapted to follow the fluid level in said reservoir means; magnetically operated switch means located in said wall, said switch means having a pair of contacts movable from a nonactuated position to an actuated position; signal means for indicating a predetermined fluid level in said reservoir means; electrical circuit means operatively connecting said signal means with said switch means; and magnetic means fixedly connected to said diaphragm means for actuating said switch means when said diaphragm means moves near said switch means, said switch means being actuated upon movement of said pair of contacts from said non-actuated position to said actuated position.
Claim 3
Dependent Claim
142 words
The invention of claim 1 wherein said switch means comprises: a hermetic non-conductive tube having a pair of magnetic contact elements extending longitudinally inwardly from the respective ends of said tube with normally resiliently spaced overlapping end portions adapted to be drawn into said actuated position by said magnetic means; electrical lead means connected to the respective outer ends of said magnetic contact elements and extending through said tube at either end; a terminal blade attached to the outer end of each of said electrical leads and disposed parallel with said tube therebetween for completing an electrical circuit to the exterior end of said switching means and for providing external connection of said electric circuit means to said switching means; and a resilient body within which said tube, a portion of said leads and a portion of said terminal blades are encapsulated.
Claim 4
Dependent Claim
146 words
The invention of claim 1 wherein: said switch means comprises a hermetic non-conductive tube having a pair of magnetic contact elements extending longitudinally inwardly from the respective ends of said tube with normally resilient contacting overlapping end portions adapted to be drawn apart by said magnetic means such that said signal means is actuated; electrical lead means connected to the respective outer ends of said magnetic contact elements and extending through said tube at either end; a terminal blade attached to the outer end of each of said electrical leads and disposed parallel with said tube therebetween for completing an electrical circuit to the exterior end of said switching means and for providing external connection of said electrical circuit means to said switching means; and a resilient body within which said tube, a portion of said leads and a portion of said terminal blades are encapsulated.
References Cited (Backward Citations)
US3577121A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1975-07-18 | 1976-01-17 | 1976-07-18 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-07-18 | 1980-01-17 | 1980-07-18 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-07-18 | 1984-01-17 | 1984-07-18 | $7700.00 | Window Closed / Lapsed |