US3681546A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Level detector
Assignee: BP PLC
•
Filing: 1970-12-23
•
Granted: 1972-08-01
•
Expires: 1990-12-23
Abstract
Abstract A pneumatic level detector has a probe connected to a pneumatic amplifier, the output of which is supplied to a pneumatic relay. When a liquid reaches the level of the probe it blocks the probe and the consequential rise of pressure is amplified so that the pneumatic relay is activated. The relay may operate an electric Switch.
Inventors
- 👤 Rene Georges Coin
- 👤 Robert-Justin Croo
- 👤 Pierre Henri Meuret
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 17:25
CPC Classifications
G; G01; G01F; G01F23/00; G01F23/14; G01F23/18; G01F23/185; Y; Y10; Y10T; Y10T137/00; Y10T137/2278; Y10T137/7287
Claims Analysis
Total Claims: 5
Claim 1
Independent Claim
123 words
A pneumatic level detector which comprises a pneumatic amplifier having an input side and an output side, a probe tube which is connected to the input side of the pneumatic amplifier so that the pneumatic amplifier amplifies the increase in pressure which occurs when the opening of the probe tube is blocked and a pneumatic relay having a primary which is connected to the output of the pneumatic amplifier and a secondary which includes a vent and an outlet which is connected to the vent when the primary receives a low pressure and the secondary also includes an inlet adapted for connection to a source of gas at high pressure which is connected to the outlet when the primary receives a high pressure.
Claim 2
Dependent Claim
123 words
A pneumatic level detector which comprises a pneumatic amplifier having an input side and an output side, a probe tube which is connected to the input side of the pneumatic amplifier so that the pneumatic amplifier amplifies the increase in pressure which occurs when the opening of the probe tube is blocked and a pneumatic relay having a primary which is connected to the output of the pneumatic amplifier and a secondary which includes a vent and an outlet which is connected to the vent when the primary receives a low pressure and the secondary also includes an inlet adapted for connection to a source of gas at high pressure which is connected to the outlet when the primary receives a high pressure.
Claim 3
Dependent Claim
80 words
A level detector according to claim 1, in which the pneumatic amplifier comprises a spring membrane which separates an input chamber connected to the probe from a vented output chamber connected to the primary of the pneumatic relay, the connection terminating in a nozzle close to the membrane, whereby an increase in pressure in the input chamber causes the membrane to move towards the nozzle thereby restricting flow and hence passing an amplified rise of pressure to the pneumatic relay.
Claim 4
Dependent Claim
90 words
A level detector according to claim 2, in which the secondary of the pneumatic relay comprises an outlet chamber connected to an adjacent inlet chamber via an inlet valve and to a vent chamber via a vent valve, the inlet valve and the veNt valve having a common actuator arranged so that when one is shut the other is open, the actuator being operatively connected to the output of the amplifier so as to close the vent valve and open the inlet valve when the amplifier provides a high pressure.
Claim 5
Dependent Claim
19 words
A level detector according to claim 3, in which the pneumatic relay is operatively connected to an electric switch.
References Cited (Backward Citations)
US2833411A
Cited
US2988099A
Cited
US3006595A
Cited
US2910999A
Cited
US3058672A
Cited
US3200971A
Cited
US3181556A
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 |