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US3680579A Expired / Lapsed US ⏱️ 0.0 years remaining

Liquid level detecting apparatus

Assignee: Tokico Ltd
•
Filing: 1970-10-19
•
Granted: 1972-08-01
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Expires: 1990-10-19
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Abstract

Abstract A liquid level detecting apparatus detects a level of the surface of the supplied liquid by use of a liquid level sensing and detecting means. The apparatus comprises a fluidic device which has its input controlled in response to the liquid surface level sensed by the liquid level sensing means and thereby changes its output. Issuance of alarm, stopping of liquid supply and the like operations are performed by changing over the output of the fluidic device.

Inventors

  • 👤 Takeo Hisada
  • 👤 Fumio Nakajima
  • 👤 Takeshi Nishi
  • 👤 Kunro Sugiyama

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-11-01 04:05
CPC Classifications
B; B67; B67D; B67D7/00; B67D7/06; B67D7/36; B67D7/362; B67D7/365; B67D7/367; G; G01; G01F; G01F23/00; G01F23/04; G01F23/14; G01F23/16; G01F23/161; G01F23/165; G01F23/167; G01F23/30; G01F23/56; G01F23/58; G01F23/585; Y; Y10; Y10T; Y10T137/00; Y10T137/206; Y10T137/2065

Claims Analysis

Total Claims: 7
Claim 1
Independent Claim 167 words
A liquid level detecting apparatus comprising a compressed air source; a fluidic device having a supply port supplied with compressed air from the compressed air source, an input port and output port; a liquid level sensing means, said sensing means being supplied with compressed air from said compressed air source and providing a pressure controlled by the exhaustion of said compressed air to the atmosphere responsive to the level of the liquid, the liquid level dependent pressure in said sensing means being supplied to the input port of the fluidic device; an air-operated changeover valve which is changed over by variation of output of the fluidic device; and an operating means variable in its condition by the changing of output of the fluidic device, wherein said output of the output port of the fluidic device is changed over by the input air pressure supplied to the input port, and said operating means is supplied with the compressed air from the compressed air source through the changeover valve.
Claim 2
Dependent Claim 167 words
A liquid level detecting apparatus comprising a compressed air source; a fluidic device having a supply port supplied with compressed air from the compressed air source, an input port and output port; a liquid level sensing means, said sensing means being supplied with compressed air from said compressed air source and providing a pressure controlled by the exhaustion of said compressed air to the atmosphere responsive to the level of the liquid, the liquid level dependent pressure in said sensing means being supplied to the input port of the fluidic device; an air-operated changeover valve which is changed over by variation of output of the fluidic device; and an operating means variable in its condition by the changing of output of the fluidic device, wherein said output of the output port of the fluidic device is changed over by the input air pressure supplied to the input port, and said operating means is supplied with the compressed air from the compressed air source through the changeover valve.
Claim 3
Dependent Claim 141 words
The apparatus of claim 1, in which said liquid level sensing means comprises a first nozzle supplied with the compressed air from the compressed air source and jetting the air into the atmosphere, a second nozzle connected to the input port of the fluidic device and having its jetting port opposite to the first nozzle, an air pipe communicating between the first and second nozzles through a pressure reducing valve, and a shield plate floating on the liquid and movable upwardly and downwardly responsive to the liquid level, said shield plate being capable of locating between the first and second nozzles, said input port receiving the input from the air pipe when the shield plate is not located between the first and second nozzles but not receiving the input when the shield plate is located between the first and second nozzles.
Claim 4
Dependent Claim 137 words
The apparatus of claim 1, which further comprises an OR gate means communicating with the compressed air source side and the output side of the changeover valve and producing an output when the compressed air is present at least in either one of the compressed air source side or the output side of the changeover valve, wherein said operating means is a liquid supply operating valve provided in a liquid supply pipe to open while it receives the compressed air, said changeover valve being provided between the compressed air source and the operating valve, said output of the fluidic device is changed over so as to change the changeover valve to non-communicating condition when the liquid level sensing means senses a liquid level as predetermined, said OR gate means making self-holding of communication of the changeover valve.
Claim 5
Dependent Claim 74 words
The apparatus of claim 3, which further comprises a flowmeter provided in the liquid supply pipe, a fixed quantity signal emission means cooperating with the flowmeter and emitting a fixed quantity air signal when the flow quantity reaches a predetermined quantity and a NOT device being interposed between the output side of the fluidic device and the changeover valve and performing a NOT operation by the signal from the fixed quantity signal emission means.
Claim 6
Dependent Claim 66 words
The apparatus of claim 1 in which said operating means is an alarm means operated by the compressed air from the compressed air source through the changeover valve, and said output of the fluidic device is changed over to changeover the air-operated changeover valve so that the alarm means is operated by the compressed air when the liquid level sensing means detects a predetermined liquid level.
Claim 7
Dependent Claim 75 words
The apparaTus of claim 1 in which said operating means is an open-close valve provided in a liquid supply pipe and operated by the the compressed air from the compressed air source through the changeover valve, and said output of the fluidic device is changed over to change over the air-operated changeover valve so that the open-close valve is closed by the compressed air when the liquid level sensing means detects a predetermined liquid level.

References Cited (Backward Citations)

US3277914A Cited
US3331380A Cited
US3538931A Cited

USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 1975-08-01 1976-01-31 1976-08-01 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 1979-08-01 1980-01-31 1980-08-01 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 1983-08-01 1984-01-31 1984-08-01 $7700.00 Window Closed / Lapsed

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