US4166381A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Apparatus for determining the viscosity of fluids
Assignee: TA Instruments Inc
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Filing: 1978-02-24
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Granted: 1979-09-04
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Expires: 1998-02-24
Abstract
Abstract The apparatus described includes a fixed plate and a movable plate mounted to vibrate relative to the fixed plate in a plane parallel to the plane of the fixed plate. The plates are spaced apart so that fluid can be placed therebetween. A drive system maintains the movable plate vibrating at its resonant frequency. The drive system uses a sinusoidal drive with a linear transducer to facilitate determination of viscosity simply by measuring the peak driving force.
Inventors
- 👤 Lecon Woo
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 20:50
CPC Classifications
G; G01; G01N; G01N11/00; G01N11/10; G01N11/16; G01N11/162; G01N11/165
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
82 words
An apparatus for the measurement of the viscosity of fluid materials comprising, in combination: a fixed plate; a flexible vibratory means; a movable plate mounted on said vibratory means for vibratory movement in a plane parallel to the plane of said fixed plate; said plates being parallel and spaced apart to receive said fluid materials therebetween; drive means for maintaining said vibratory means in vibration at its resonant frequency using a sinusoidally varying driving force; and means for measuring said driving force.
Claim 2
Independent Claim
82 words
An apparatus for the measurement of the viscosity of fluid materials comprising, in combination: a fixed plate; a flexible vibratory means; a movable plate mounted on said vibratory means for vibratory movement in a plane parallel to the plane of said fixed plate; said plates being parallel and spaced apart to receive said fluid materials therebetween; drive means for maintaining said vibratory means in vibration at its resonant frequency using a sinusoidally varying driving force; and means for measuring said driving force.
Claim 3
Dependent Claim
19 words
The apparatus of claim 1 wherein said vibrating means includes an elongated member with said movable plate mounted thereon.
Claim 4
Dependent Claim
29 words
The apparatus of claim 2 which also includes flexure pivots for mounting said elongated member for pivotal motion in a plane parallel to the plane of said movable plate.
Claim 5
Dependent Claim
14 words
The apparatus of claim 3 wherein said flexure pivots have a known spring constant.
Claim 6
Dependent Claim
25 words
The apparatus of claim 4 wherein said movable plate is located above said fixed plate and defines a hole therein to accommodate said fluid materials.
Claim 7
Dependent Claim
25 words
The apparatus of claim 1 wherein said movable plate is located above said fixed plate and defines a hole therein to accommodate said fluid materials.
Claim 8
Dependent Claim
38 words
The apparatus of claim 1 wherein said vibratory means is maintained in vibration at a known amplutide, and said driving force is linearly proportional to a driving voltage, and said driving force is measured by measuring said voltage.
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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) | 1982-09-03 | 1983-03-05 | 1983-09-04 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1986-09-03 | 1987-03-05 | 1987-09-04 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1990-09-03 | 1991-03-05 | 1991-09-04 | $7700.00 | Window Closed / Lapsed |