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US4175435A Expired / Lapsed US ⏱️ 0.0 years remaining

Liquid level detecting device

Assignee: Nifco Inc
•
Filing: 1978-08-10
•
Granted: 1979-11-27
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Expires: 1998-08-10
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Abstract

Abstract A liquid level detecting device which comprises an annular float adapted to float constantly on the surface of a body of liquid subjected to level detection, a barrel passing through the float so as to guide the motion of the float, permanent magnets disposed in the float and a magnetically operatable lead switch disposed in the barrel permits the detection of liquid level to be effected on the principle that the lead switch is magnetically turned into its ON state at the time that the float, while in motion, reaches the position at which the barrel incorporates the lead switch.

Inventors

  • 👤 Kunio Hara

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-11-09 16:04
CPC Classifications
G; G01; G01F; G01F23/00; G01F23/30; G01F23/64; G01F23/68; G01F23/70; Y; Y10; Y10S; Y10S73/00; Y10S73/05

Claims Analysis

Total Claims: 4
Claim 1
Independent Claim 135 words
A liquid level detecting device, comprising a float provided with an inner hole internally incorporating permanent magnets and a barrel inserted through the inner hole of said float to guide the movement of the float and internally provided with a magnetically operatable lead switch, whereby the movement of the float which constantly follows the movement of a liquid surface selectively actuates the lead switch inside the barrel to permit detection of the liquid said float being formed in the shape of a horseshoe substantially to enclose the barrel and said float being provided with a rod member with a portion of the rod member rotatably fastened on a stationary means so as to permit the float to enjoy freedom of vertical movement relative to the barrel and selectively actuate the lead switch in the barrel.
Claim 2
Dependent Claim 135 words
A liquid level detecting device, comprising a float provided with an inner hole internally incorporating permanent magnets and a barrel inserted through the inner hole of said float to guide the movement of the float and internally provided with a magnetically operatable lead switch, whereby the movement of the float which constantly follows the movement of a liquid surface selectively actuates the lead switch inside the barrel to permit detection of the liquid said float being formed in the shape of a horseshoe substantially to enclose the barrel and said float being provided with a rod member with a portion of the rod member rotatably fastened on a stationary means so as to permit the float to enjoy freedom of vertical movement relative to the barrel and selectively actuate the lead switch in the barrel.
Claim 3
Dependent Claim 78 words
A liquid level detecting device for determining the presence or absence of a liquid, which comprises a hollow barrel provided in the inner wall thereof with permanent magnets and a float incorporating a lead switch and held inside the cavity formed inside the barrel, whereby the movement of said float which constantly follows the movement of the liquid surface selectively actuates the lead switch inside the barrel to permit detection of the presence or absence of the liquid.
Claim 4
Dependent Claim 78 words
A liquid level detecting device for determining the presence or absence of a liquid, which comprises a hollow barrel provided in the inner wall thereof with permanent magnets and a float incorporating a lead switch and held inside the cavity formed inside the barrel, whereby the movement of said float which constantly follows the movement of the liquid surface selectively actuates the lead switch inside the barrel to permit detection of the presence or absence of the liquid.

References Cited (Backward Citations)

US3200645A Cited
US3633193A Cited
US3874237A Cited
US4064755A Cited
US4084436A Cited
US4081639A Cited

USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 1982-11-26 1983-05-28 1983-11-27 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 1986-11-26 1987-05-28 1987-11-27 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 1990-11-26 1991-05-28 1991-11-27 $7700.00 Window Closed / Lapsed

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