US4144752A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Ultrasonically operative device for determining physical quantities of a medium
Assignee: Danfoss AS
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Filing: 1977-10-19
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Granted: 1979-03-20
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Expires: 1997-10-19
Abstract
Abstract The invention relates to an ultrasonically operative device operable with an ultrasonic signal having a predetermined wave length for measuring physical quantities such as the flow speed of a medium such as water. The device includes an ultrasonic transmitter and an ultrasonic receiver with a tube unit therebetween defining a transmission path for the medium. The tube unit has an internal diameter less than about fifteen times the wavelength of the signal. The tube unit includes an outer metal tube and an inner plastics liner of a plastic such as a polyamide.
Inventors
- 👤 Soren Lolk
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 09:27
CPC Classifications
G; G01; G01F; G01F1/00; G01F1/66; G01F1/662; G01N; G01N29/00; G01N29/02; G01N29/024; G01N2291/00; G01N2291/02; G01N2291/028; G01N2291/02836
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
81 words
An ultrasonically operative device operable with an ultrasonic signal having a predetermined wave length for determining physical quantities such as the flow speed of a medium, comprising, an ultrasonic transmitter and an ultrasonic receiver, tube means defining a transmission path extending between said transmitter and said receiver, said tube means having an internal diameter of less than about 15 times said predetermined wave length, said tube means having an inner surface of a material having a lower acoustic impedance than metal.
Claim 2
Dependent Claim
81 words
An ultrasonically operative device operable with an ultrasonic signal having a predetermined wave length for determining physical quantities such as the flow speed of a medium, comprising, an ultrasonic transmitter and an ultrasonic receiver, tube means defining a transmission path extending between said transmitter and said receiver, said tube means having an internal diameter of less than about 15 times said predetermined wave length, said tube means having an inner surface of a material having a lower acoustic impedance than metal.
Claim 3
Dependent Claim
12 words
A device according to claim 1 wherein said material is a plastic.
Claim 4
Dependent Claim
20 words
A device according to claim 2 wherein said tube means comprises an outer metal tube and an inner plastic liner.
Claim 5
Dependent Claim
18 words
A device according to claim 3 wherein the thickness of said plastic liner is 0.5 to 1.5 mm.
Claim 6
Dependent Claim
12 words
A device according to claim 2 wherein said plastic is a polyamide.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1982-03-19 | 1982-09-18 | 1983-03-20 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1986-03-19 | 1986-09-18 | 1987-03-20 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1990-03-19 | 1990-09-18 | 1991-03-20 | $7700.00 | Window Closed / Lapsed |