US3797514A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Automated filler and lever controller for liquid nitrogen
Assignee: Gulf Research and Development Co
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Filing: 1972-06-27
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Granted: 1974-03-19
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Expires: 1992-06-27
Abstract
Abstract A system of supplying a liquid to a relatively small use vessel, such as a point of use inside an instrument, from a relatively large supply vessel remote from the use vessel, such as a large flask external to the instrument. The invention comprises a fluids conduit system controlled by a circuit operated by changing liquid level in the use vessel to pressurize the supply vessel to thereby flow liquid over to the use vessel. The circuit includes an RC portion to set the length of time that liquid flows.
Inventors
- 👤 R Byers
- 👤 J Schmitt
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-03 11:38
CPC Classifications
F; F17; F17C; F17C13/00; F17C13/02; F17C13/021; F16; F16K; F16K21/00; F16K21/04; F16K21/18; F16K21/185; F17C2201/00; F17C2201/01; F17C2201/0104; F17C2201/0119; F17C2201/05; F17C2201/056; F17C2203/00; F17C2203/03; F17C2203/0391; F17C2203/06; F17C2203/0634; F17C2203/0636; F17C2205/00; F17C2205/03; F17C2205/0302; F17C2205/0323; F17C2205/0326; F17C2221/00; F17C2221/01; F17C2221/014; F17C2223/00; F17C2223/01; F17C2223/0146; F17C2223/0153; F17C2223/0161; F17C2223/03; F17C2223/033; F17C2227/00; F17C2227/01; F17C2227/0107; F17C2227/04; F17C2250/00; F17C2250/04; F17C2250/0404; F17C2250/0408; F17C2250/0413; F17C2250/0417; F17C2250/06; F17C2250/0605; F17C2250/061; F17C2250/0636; F17C2250/0673; F17C2250/07; F17C2250/072; F17C2265/00; F17C2265/03; F17C2265/031; F17C2265/032; F17C2265/037; F17C2270/00; F17C2270/05; F17C2270/0509; Y; Y10; Y10T; Y10T137/00; Y10T137/2931; Y10T137/3115; Y10T137/3127; Y10T137/314; Y10T137/3143; Y10T137/7287; Y10T137/7306
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
131 words
Apparatus for flowing liquid from a supply vessel to a use vessel for a predetermined length of time, comprising means to supply pressurized gas to said supply vessel above the liquid therein, means to flow liquid out of said supply vessel under the influence of said pressurized gas, means to sense when said liquid falls below a predetermined level in said use vessel, circuit means operated by said sensing means, said circuit means including means to commence the supply of said pressurized gas to said supply vessel upon operation of said sensing means, and said circuit means including adjustable means to control the length of time pressurized gas is supplied to the upper end of said supply vessel and to thereafter stop the flow of pressurized gas to said supply vessel.
Claim 2
Dependent Claim
131 words
Apparatus for flowing liquid from a supply vessel to a use vessel for a predetermined length of time, comprising means to supply pressurized gas to said supply vessel above the liquid therein, means to flow liquid out of said supply vessel under the influence of said pressurized gas, means to sense when said liquid falls below a predetermined level in said use vessel, circuit means operated by said sensing means, said circuit means including means to commence the supply of said pressurized gas to said supply vessel upon operation of said sensing means, and said circuit means including adjustable means to control the length of time pressurized gas is supplied to the upper end of said supply vessel and to thereafter stop the flow of pressurized gas to said supply vessel.
Claim 3
Dependent Claim
40 words
The combination of claim 1, wherein said liquid is liquid nitrogen, means to vent boil-off gaseous nitrogen from the upper end of said supply vessel, and means to close said vent means when said pressurized gas supply means are operative.
Claim 4
Dependent Claim
27 words
The combination of claim 2, and pin-hole bleeder means on said vent means to reduce the rate and amount of boil-off gaseous nitrogen leaving said supply vessel.
Claim 5
Dependent Claim
49 words
The combination of claim 1, said means to flow liquid out of said supply vessel comprising a snorkel tube extending down to a position closely adjacent the bottom of said supply vessel, whereby substantially all of the liquid in said supply vessel will be flowed to said use vessel.
Claim 6
Dependent Claim
34 words
The combination of claim 1, said sensing means comprising means to activate and de-activate portions of said circuit means when said device does not sense and does sense said liquid in said use vessel.
Claim 7
Dependent Claim
88 words
The combination of claim 1, said means in said circuit means to time and stop the flow of pressurized gas to said supply vessel comprising a unijunction transistor and an RC timing circuit so arranged that the charging time of said RC circuit controls the firing of said transistor, a variable resistance in said RC circuit, a normally closed solenoid valve to control the flow of said pressurized gas to the upper end of said supply vessel, and wherein said unijunction transistor controls said normally closed solenoid valve.
Claim 8
Dependent Claim
98 words
The combination of claim 6, wherein said liquid is liquid nitrogen, means to vent boil-off gaseous nitrogen from the upper end of said supply vessel, means to close said vent means when said pressurized gas supply means are operative, a relay in said circuit means, said relay including a first pair of normally closed contacts in series circuit with the coil of said normally closed solenoid valve, said relay including a second pair of normally closed contacts to control the charging of said RC circuit, and wherein the firing of said transistor operates the coil of said relay.
Claim 9
Dependent Claim
30 words
The combination of claim 7, said relay including a pair of normally open contacts in series circuit with said relay coil to establish a holding circuit for said relay coil.
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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) | 1977-03-18 | 1977-09-17 | 1978-03-19 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-03-18 | 1981-09-17 | 1982-03-19 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-03-18 | 1985-09-17 | 1986-03-19 | $7700.00 | Window Closed / Lapsed |