US3893339A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Liquid level indicator
Assignee: Illinois Tool Works Inc
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Filing: 1974-03-18
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Granted: 1975-07-08
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Expires: 1994-03-18
Abstract
Abstract An optical liquid indicator having a light transparent rod with a reflective lower surface and a collar or cap with a central aperture which receives the upper end of the rod is disclosed. The collar is preferably formed of a plastic material with a pair of inwardly projecting annular sealing members. One of the sealing members is rigid and the other one is flexible. The upper portion of the indicator rod has a relatively wide surface which diverges outwardly from the rod and a relatively narrow surface which is inclined toward the rod, and there is an outwardly projecting disc at the upper viewing surface. The collar is forced upwardly over the rod so that the rigid sealing member snaps into place against the inwardly inclined surface and the flexible sealing member is bent inwardly against the lower surface of the disc so as to form a seal between the collar and the rod.
Inventors
- 👤 Robert Richard Melone
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 19:15
CPC Classifications
G; G01; G01F; G01F23/00; G01F23/22; G01F23/28; G01F23/284; G01F23/292; G01F23/2921; G01F23/2922
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
178 words
A liquid indicator comprising an elongated rod of a light transmitting material having an upper viewing surface and a lower reflective surface, a projecting disc near its upper viewing surface having a diameter greater than the diameter of the rod, an outwardly inclined surface below said disc which extends upwardly, an inwardly inclined surface above said outwardly inclined surface, a closure member which surrounds said rod, an annular sealing element extending inwardly towards said rod from the inner periphery of said closure member comprising a relatively rigid downwardly extending sealing member and a relatively flexible upwardly extending sealing member constructed so that said closure member is held in sealing engagement with said rod when said closure member is forced upwardly from the bottom of the said rod to the point where said rigid sealing member abuts against said inwardly inclined surface in sealing relationship and said flexible sealing member is deflected inwardly by the lower surface of said disc so as to form a seal between said lower surface, said disc, and the outer periphery of said rod.
Claim 2
Dependent Claim
178 words
A liquid indicator comprising an elongated rod of a light transmitting material having an upper viewing surface and a lower reflective surface, a projecting disc near its upper viewing surface having a diameter greater than the diameter of the rod, an outwardly inclined surface below said disc which extends upwardly, an inwardly inclined surface above said outwardly inclined surface, a closure member which surrounds said rod, an annular sealing element extending inwardly towards said rod from the inner periphery of said closure member comprising a relatively rigid downwardly extending sealing member and a relatively flexible upwardly extending sealing member constructed so that said closure member is held in sealing engagement with said rod when said closure member is forced upwardly from the bottom of the said rod to the point where said rigid sealing member abuts against said inwardly inclined surface in sealing relationship and said flexible sealing member is deflected inwardly by the lower surface of said disc so as to form a seal between said lower surface, said disc, and the outer periphery of said rod.
Claim 3
Dependent Claim
39 words
A liquid indicator as set forth in claim 1 wherein said closure member is formed of a plastic material and said sealing element is an integral part of said closure member and said sealing members have an annular shape.
Claim 4
Dependent Claim
17 words
A liquid indicator as set forth in claim 2 wherein said closure member is formed of polypropylene.
Claim 5
Dependent Claim
30 words
A liquid indicator as claimed in claim 1 wherein said outwardly inclined surface is of a relatively long dimension and said inwardly inclined surface is of a relatively short dimension.
Claim 6
Dependent Claim
27 words
A liquid indicator as set forth in claim 4 wherein a relatively short transition surface is disposed between said outwardly inclined surface and said inwardly inclined surface.
Claim 7
Dependent Claim
75 words
A liquid indicator as set forth in claim 1 wherein the outer periphery of said closure member has a plurality of ribs each of which have a surface that curves in a first direction and a flat surface that is directed in a second direction whereby said closure means may be easily inserted into a receiving member in one direction but resists removal from said receiving member when force is applied in the opposite direction.
Claim 8
Dependent Claim
31 words
A liquid indicator as set forth in claim 2 wherein said outwardly inclined surface is of a relatively long dimension and said inwardly inclined surface is of a relatively short dimension.
Claim 9
Dependent Claim
27 words
A liquid indicator as set forth in claim 7 wherein a relatively short transition surface is disposed between said outwardly inclined surface and said inwardly inclined surface.
Claim 10
Dependent Claim
75 words
A liquid indicator as set forth in claim 8 wherein the outer periphery of said closure member has a plurality of ribs each of which have a surface that curves in a first direction and a flat surface that is directed in a second direction whereby said closure means may be easily inserted into a receiving member in one direction but resists removal from said receiving member when force is applied in the opposite direction.
Claim 11
Dependent Claim
17 words
A liquid indicator as set forth in claim 9 wherein said closure member is formed of polypropylene.
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) | 1978-07-07 | 1979-01-06 | 1979-07-08 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-07-07 | 1983-01-06 | 1983-07-08 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-07-07 | 1987-01-06 | 1987-07-08 | $7700.00 | Window Closed / Lapsed |