US3750124A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Fluid level switch
Assignee: Bendix Corp
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Filing: 1971-09-20
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Granted: 1973-07-31
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Expires: 1991-09-20
Abstract
Abstract An indicator for warning of low fluid level in a master cylinder reservoir having an electrical reed switch mounted horizontally in the wall of a fluid reservoir and connected to appropriate indicator circuitry for warning the vehicle operator of the low fluid condition. The reed switch is actuated by a permanent magnet encapsulated in a float whenever the fluid level becomes dangerously low.
Inventors
- 👤 C Barnes
- 👤 R Kosaeski
- 👤 J Putt
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 19:25
CPC Classifications
B; B60; B60T; B60T17/00; B60T17/18; B60T17/22; B60T17/225; G; G01; G01F; G01F23/00; G01F23/30; G01F23/32; G01F23/36; G01F23/38; G01F23/64; G01F23/68; G01F23/70; G01F23/72; G01F23/74
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
358 words
In a master cylinder: a housing having a reservoir therein containing a fluid, said fluid being subjected to sloshing; switch means having one end fixed in a side of said housing and the other end extending into said reservoir, said switch means having a pair of contacts movable from a non-actuated position to an actuated position; a source of electrical energy connected to said switch means; float means having a transverse slot surrounding said switch means and a transverse hold adjacent said transverse slot, said transverse slot being elongated in a vertical direction for permitting vertical movement of the float means relative to the switch means in response to changes in the level of the fluid in said reservoir; cover means for enclosing said float means to form a fluid level indicator chamber, said cover means having a portion thereof cut away to a predetermined opening size to permit fluid communication between said reservoir and indicator chamber, saidopening in the cover means attenuating the effect of sloshing of said fluid in said reservoir by controlling the fluid flow communication into said indicator means, said cover means having a first leg and a second leg extending parallel to the transverse slot and an end cap connecting the first leg with the second leg, said end cap holding said other end of the switching means in a fixed position with respect to said cover means, said first and second legs guiding said float means in the reservoir to maintain the transverse slot and hole in the float means in a vertical position; indicator means for informing an operator of a predetermined fluid level in said reservoir; electrical circuit means connecting said source of electrical energy with said indicator means through one end of the switch means, the other end of said switch means, said end cap, and first and second legs; and magnetic means located in said transverse hole in said float means for actuating said switch means in response to a predetermined vertical position of said float means in said reservoir, said switch means upon actuation permitting said electrical energy from said source to flow and energize said indicator.
Claim 2
Dependent Claim
358 words
In a master cylinder: a housing having a reservoir therein containing a fluid, said fluid being subjected to sloshing; switch means having one end fixed in a side of said housing and the other end extending into said reservoir, said switch means having a pair of contacts movable from a non-actuated position to an actuated position; a source of electrical energy connected to said switch means; float means having a transverse slot surrounding said switch means and a transverse hold adjacent said transverse slot, said transverse slot being elongated in a vertical direction for permitting vertical movement of the float means relative to the switch means in response to changes in the level of the fluid in said reservoir; cover means for enclosing said float means to form a fluid level indicator chamber, said cover means having a portion thereof cut away to a predetermined opening size to permit fluid communication between said reservoir and indicator chamber, saidopening in the cover means attenuating the effect of sloshing of said fluid in said reservoir by controlling the fluid flow communication into said indicator means, said cover means having a first leg and a second leg extending parallel to the transverse slot and an end cap connecting the first leg with the second leg, said end cap holding said other end of the switching means in a fixed position with respect to said cover means, said first and second legs guiding said float means in the reservoir to maintain the transverse slot and hole in the float means in a vertical position; indicator means for informing an operator of a predetermined fluid level in said reservoir; electrical circuit means connecting said source of electrical energy with said indicator means through one end of the switch means, the other end of said switch means, said end cap, and first and second legs; and magnetic means located in said transverse hole in said float means for actuating said switch means in response to a predetermined vertical position of said float means in said reservoir, said switch means upon actuation permitting said electrical energy from said source to flow and energize said indicator.
Claim 3
Dependent Claim
121 words
The invention of claim 1 wherein said switch means includes: a hermetic, non-conductive, non-magnetic tube having a pair of magnetic contact elements extending longitudinally inwardly from the respective ends of said tube with normally overlapping end portions adapted to be moved by said magnetic means from a non-actuated position to an actuated position; electrical lead means connected to the respective ends of said magnetic contact elements and extending through said tube at either end; terminal blades attached to the respective outer ends of said leads and disposed for external connection of said switch means to said electrical circuit 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
30 words
The invention of claim 2 wherein said overlapping end portions of the contact elements are normally resiliently spaced and are adapted to be drawn into contact by said magnetic means.
Claim 5
Dependent Claim
29 words
The invention of claim 2 wherein said overlapping end portions of the contact elements are normally in contact and are adapted to be drawn apart by said magnetic means.
Claim 6
Dependent Claim
25 words
The invention as recited in claim 2 wherein said switch means is sealed from said fluid to prevent leakage of electrical energy through said fluid.
Claim 7
Dependent Claim
30 words
The invention as recited in claim 2 wherein said float means is pivotally retained adjacent said switch means to correspondingly move said magNetic means with changes in the fluid level.
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) | 1976-07-30 | 1977-01-29 | 1977-07-31 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-07-30 | 1981-01-29 | 1981-07-31 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-07-30 | 1985-01-29 | 1985-07-31 | $7700.00 | Window Closed / Lapsed |