US4087663A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Liquid level contents indicators for vehicle hydraulic systems
Assignee: Girling Ltd
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Filing: 1976-09-24
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Granted: 1978-05-02
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Expires: 1996-09-24
Abstract
Abstract In a liquid level contents indicator for a vehicle hydraulic system of the float-operated electric switch type manually operable mechanism for testing the circuit comprises a push-button located in an end closure cap for a reservoir and the push-button acts on contacts of the electric circuit through a resilient diaphragm which also acts as a return spring for the push-button and provides a seal between the push button and the cap.
Inventors
- 👤 Patrick Frank Sawyer
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-07 17:41
CPC Classifications
G; G01; G01F; G01F23/00; G01F23/30; G01F23/64
Claims Analysis
Total Claims: 5
Claim 1
Independent Claim
143 words
A liquid level contents indicator for a vehicle hydraulic system comprising spaced contacts of an electric circuit, an electric switch member operative to engage with both contacts and complete the electric circuit, indicating means energised by said electric circuit, means operating said switch member such that the electric circuit is completed when the level of liquid in a reservoir for hydraulic fluid in said system is below a predetermined value, an end closure cap for said reservoir, said closure cap including a hollow housing and a plug closing one end of said housing, a manually operable push button located in said plug for testing said circuit, and a resilient diaphragm clamped at its peripheral edge between said plug and said housing, said diaphragm comprising means acting as a return spring for said button and providing a seal between said plug and said housing.
Claim 2
Dependent Claim
143 words
A liquid level contents indicator for a vehicle hydraulic system comprising spaced contacts of an electric circuit, an electric switch member operative to engage with both contacts and complete the electric circuit, indicating means energised by said electric circuit, means operating said switch member such that the electric circuit is completed when the level of liquid in a reservoir for hydraulic fluid in said system is below a predetermined value, an end closure cap for said reservoir, said closure cap including a hollow housing and a plug closing one end of said housing, a manually operable push button located in said plug for testing said circuit, and a resilient diaphragm clamped at its peripheral edge between said plug and said housing, said diaphragm comprising means acting as a return spring for said button and providing a seal between said plug and said housing.
Claim 3
Dependent Claim
61 words
A liquid level contents indicator as claimed in claim 1, wherein a float is accommodated in said housing, said plug has a central bore through which said push-button projects and a radial flange is provided in said housing adjacent to an inner end of said push-button, said resilient diaphragm being clamped at its peripheral edge between said plug and said flange.
Claim 4
Dependent Claim
48 words
A liquid level contents indicator as claimed in claim 2, wherein said flange has an outwardly directed axial extension and said plug has an inwardly directed skirt spaced radially from said extension but overlapping it so that the peripheral edge of said diaphragm is distended and imprisoned therebetween.
Claim 5
Dependent Claim
142 words
A liquid level contents indicator as claimed in claim 1, wherein said housing comprises first and second housing parts and said second housing part comprises an upstanding cylindrical body extending out of said first part and a downwardly depending skirt projecting into said first part, said plug and said resilient diaphragm being located in said cylindrical body, and a sleeve housed within said skirt and cylindrical body abuts against said flange, and wherein said contacts of the electrical circuit are embedded in said sleeve and the walls of said body, and said metal switch member has a downwardly depending stem and is engageable with both contacts, said float being engageable with the lower end of said stem so as to hold said switch out of engagement with said contacts when the fluid level in said reservoir is above a predetermined minimum level.
References Cited (Backward Citations)
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1981-05-01 | 1981-10-31 | 1982-05-02 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1985-05-01 | 1985-10-31 | 1986-05-02 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1989-05-01 | 1989-10-31 | 1990-05-02 | $7700.00 | Window Closed / Lapsed |