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US3728704A Expired / Lapsed US ⏱️ 0.0 years remaining

Automatic transmission fluid level indicator

Assignee: Individual
•
Filing: 1971-04-19
•
Granted: 1973-04-17
•
Expires: 1991-04-19
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Abstract

Abstract An automatic transmission fluid level indicator having a removable rod with an area of reduced diameter at and extending below the desired fluid level, a float including a conductive ring surrounding the reduced area, a circuit received in the rod connects a battery with a lamp or other indicator through the conductive ring upon sufficient descent of the float to indicate a significant decline in the fluid level. The float with the conductive ring is urged downwardly by a compression spring which, however, is insufficient in force to overcome the buoyance effect of the fluid upon the float, but when the rod is drawn out of the fluid, the circuit is automatically closed. A plug on top of the shaft provides for removal of the rod from the circuit. The amount of extension of the rod into the automatic transmission casing is adjustable whereby the amount of fluid loss to energize the indicator is also adjustable.

Inventors

  • 👤 T Moore

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-11-02 14:53
CPC Classifications
H; H01; H01H; H01H35/00; H01H35/18

Claims Analysis

Total Claims: 10
Claim 1
Independent Claim 241 words
In combination with a casing which contains a non-conductive fluid, a fluid level indicator which comprises a shaft removably extending from outside of the casing into said fluid, a tube extending upwardly from said casing receiving said shaft, a tube cover connected to said shaft cooperating with the top of said tube to retain said shaft in a predetermined position relative to said casing, float means carried by said shaft, said float means including conductive bridge means, said float means being buoyant relative to said fluid and movable within limits relative to said shaft, electrically operated indicia means, resilient means mounted on said shaft relative to said float means, electrical energy producing means, and a circuit for connecting said indicia means to said energy producing means, said circuit means being received in said shaft and including a pair of contacts, said resilient means resiliently urging said float means toward said contacts with a downwardly directed force which is insufficient to overcome the buoyancy of said float means in said fluid, said circuit means being in an opened condition across said contacts, said contacts being affixed to said shaft relative to said float means whereby when said float means lowers a predetermined amount relative to said shaft due to a lowering of said fluid in said casing or withdrawal of said shaft above said fluid, said conductive bridge means conductively connects said contacts to close said circuit to energize said indicia means.
Claim 2
Dependent Claim 241 words
In combination with a casing which contains a non-conductive fluid, a fluid level indicator which comprises a shaft removably extending from outside of the casing into said fluid, a tube extending upwardly from said casing receiving said shaft, a tube cover connected to said shaft cooperating with the top of said tube to retain said shaft in a predetermined position relative to said casing, float means carried by said shaft, said float means including conductive bridge means, said float means being buoyant relative to said fluid and movable within limits relative to said shaft, electrically operated indicia means, resilient means mounted on said shaft relative to said float means, electrical energy producing means, and a circuit for connecting said indicia means to said energy producing means, said circuit means being received in said shaft and including a pair of contacts, said resilient means resiliently urging said float means toward said contacts with a downwardly directed force which is insufficient to overcome the buoyancy of said float means in said fluid, said circuit means being in an opened condition across said contacts, said contacts being affixed to said shaft relative to said float means whereby when said float means lowers a predetermined amount relative to said shaft due to a lowering of said fluid in said casing or withdrawal of said shaft above said fluid, said conductive bridge means conductively connects said contacts to close said circuit to energize said indicia means.
Claim 3
Dependent Claim 16 words
The apparatus of claim 1 wherein said float means comprises a ring which surrounds said shaft.
Claim 4
Dependent Claim 17 words
The apparatus of claim 2 wherein said ring is hollow and is composed of a conductive material.
Claim 5
Dependent Claim 16 words
The apparatus of claim 3 wherein said shaft includes a narrowed portion which receives said ring.
Claim 6
Dependent Claim 23 words
The apparatus of claim 4 wherein said resilient means is mounted relative to said narrow portion and said ring which urges said ring.
Claim 7
Dependent Claim 18 words
The apparatus of claim 5 wherein said resilient means comprises a compression spring which surrounds said narrowed portion.
Claim 8
Dependent Claim 33 words
The apparatus of claim 1 wherein adjustment means is included in the connection of said shaft to said tube cover whereby the amount of extension of said shaft into said casing is adjustable.
Claim 9
Dependent Claim 23 words
The apparatus of claim 1 wherein said casing contains an automatic transmission for a prime mover and said fluid is automatic transmission fluid.
Claim 10
Dependent Claim 20 words
The apparatus of claim 1 wherein said circuit includes plug means and receptacle in the upper aspect of said shaft.

References Cited (Backward Citations)

US1244962A Cited
US2804517A Cited
US2915605A Cited
US3098914A Cited
US3633193A Cited

USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 1976-04-16 1976-10-16 1977-04-17 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 1980-04-16 1980-10-16 1981-04-17 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 1984-04-16 1984-10-16 1985-04-17 $7700.00 Window Closed / Lapsed

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