US3926271A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Microbalance
Assignee: Individual
•
Filing: 1975-02-03
•
Granted: 1975-12-16
•
Expires: 1995-02-03
Abstract
Abstract A microbalance comprising a tapered tubular element that is clamped at one end while the other end is free to vibrate. The specimen whose mass is to be evaluated is attached to the free end of the tapered tubular element. The tapered tubular element is set into oscillation and a feedback system maintains the oscillation. The mass is determined by measuring the resonant frequency of the tapered tubular element which will change in accordance with the mass loading of the tapered tubular element.
Inventors
- 👤 Harvey Patashnick
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 06:52
CPC Classifications
G; G01; G01G; G01G3/00; G01G3/12; G01G3/16
Claims Analysis
Total Claims: 23
Claim 1
Independent Claim
199 words
A mass measuring device comprising an elongate elastic element which is tapered from a first larger end to a second smaller end and which is adapted to support a mass to be measured at its smaller end, said elastic element Being tapered so that the second moment defined as I Integral Integral v2dydx varies in a predetermined manner according to the distance from said larger end, where y is the distance from the neutral fiber of said elastic element, the product dydx is a rectangular area element in a cross-section of the elastic element lying within a plane perpendicular to the axis of said elastic element, and the integration is extended over the whole area of said cross-section, means for anchoring said first larger end so that its second smaller end and the mass carried thereby are free to oscillate, drive means for dynamically flexing said elastic element so that its smaller end will oscillate at a resonant frequency, and means for measuring the resonant frequency of oscillation of said elastic element with and without said mass, whereby the magnitude of said mass can be determined by the change in resonant frequency due to the presence of said mass.
Claim 2
Dependent Claim
199 words
A mass measuring device comprising an elongate elastic element which is tapered from a first larger end to a second smaller end and which is adapted to support a mass to be measured at its smaller end, said elastic element Being tapered so that the second moment defined as I Integral Integral v2dydx varies in a predetermined manner according to the distance from said larger end, where y is the distance from the neutral fiber of said elastic element, the product dydx is a rectangular area element in a cross-section of the elastic element lying within a plane perpendicular to the axis of said elastic element, and the integration is extended over the whole area of said cross-section, means for anchoring said first larger end so that its second smaller end and the mass carried thereby are free to oscillate, drive means for dynamically flexing said elastic element so that its smaller end will oscillate at a resonant frequency, and means for measuring the resonant frequency of oscillation of said elastic element with and without said mass, whereby the magnitude of said mass can be determined by the change in resonant frequency due to the presence of said mass.
Claim 3
Dependent Claim
13 words
A device according to claim 1 wherein said element is a solid rod.
Claim 4
Dependent Claim
16 words
A device according to claim 1 wherein said element is made of a substantially monocrystalline material.
Claim 5
Dependent Claim
18 words
A device according to claim 1 wherein said sensing means optically senses the oscillating movement of said element.
Claim 6
Dependent Claim
18 words
A device according to claim 1 wherein said sensing means magnetically senses the oscillating movement of said element.
Claim 7
Dependent Claim
50 words
A device according to claim 1 wherein said second moment varies uniformly with the distance from said larger end and becomes zero at a point L'', where L'' is an extrapolated distance from said first end which exceeds the length L of said elastic element measured from said first end.
Claim 8
Dependent Claim
26 words
A device according to claim 1 further including an enlargement on said second smaller end of said element for supporting a sample mass to be measured.
Claim 9
Dependent Claim
21 words
A device according to claim 7 wherein said enlargement is flared and has an edge surface for supporting a sample holder.
Claim 10
Dependent Claim
50 words
A device according to claim 1 wherein said element has an electrically conductive means attached to its exterior intermediate its ends, and said drive means comprises a pair of electrodes spaced from said element and means for applying a varying electrical potential between said electrodes and said electrically conductive means.
Claim 11
Dependent Claim
19 words
A device according to claim 9 wherein said element is made of material which is not an electrical conductor.
Claim 12
Dependent Claim
24 words
A device according to claim 9 further including means for operating said drive means in response to the frequency detected by said sensing means.
Claim 13
Dependent Claim
36 words
A device according to claim 9 wherein said means for applying an electrical potential comprises a source of alternating potential connected to said conductive means and means for providing a d.c. potential between said two electrodes.
Claim 14
Dependent Claim
13 words
A device according to claim 1 wherein said element is a hollow tube.
Claim 15
Dependent Claim
26 words
A device according to claim 13 wherein the interior cross-sectional area of said tube decreases progressively from said first larger end to said second smaller end.
Claim 16
Dependent Claim
42 words
A device according to claim 13 including a supporting member, and further wherein said tube has an enlarged relatively thick wall section at its first larger end, and said anchoring means clamps said enlarged relatively thick wall section to said supporting member.
Claim 17
Dependent Claim
12 words
A device according to claim 13 wherein said tube is monocrystalline alumina.
Claim 18
Dependent Claim
15 words
A device according to claim 16 wherein said tube is made of quartz or glass.
Claim 19
Dependent Claim
142 words
A mass measuring device comprising an elongate elastic element having a first end which is adapted to support a mass to be measured and a second larger end which is anchored so that said first end and the mass carried thereby are free to oscillate, said element being tapered from said second end to said first end in a predetermined manner so that said element will have a substantially constant curvature when it is flexed dynamically relative to said second end, drive mEans for dynamically flexing said element so that its said first end will oscillate at a resonant frequency, and means for sensing the resonant frequency of oscillation of said element with and without said mass, whereby the magnitude of said mass can be determined by measuring the difference in the resonant frequency of said element with and without said mass.
Claim 20
Dependent Claim
142 words
A mass measuring device comprising an elongate elastic element having a first end which is adapted to support a mass to be measured and a second larger end which is anchored so that said first end and the mass carried thereby are free to oscillate, said element being tapered from said second end to said first end in a predetermined manner so that said element will have a substantially constant curvature when it is flexed dynamically relative to said second end, drive mEans for dynamically flexing said element so that its said first end will oscillate at a resonant frequency, and means for sensing the resonant frequency of oscillation of said element with and without said mass, whereby the magnitude of said mass can be determined by measuring the difference in the resonant frequency of said element with and without said mass.
Claim 21
Dependent Claim
15 words
A device according to claim 18 wherein said elongate elastic element is a hollow tube.
Claim 22
Dependent Claim
15 words
A device according to claim 18 wherein said elongate elastic element is a solid rod.
Claim 23
Dependent Claim
18 words
A device according to claim 18 wherein said elongate elastic element is made of a substantially monocrystalline material.
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) | 1978-12-15 | 1979-06-16 | 1979-12-16 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-12-15 | 1983-06-16 | 1983-12-16 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-12-15 | 1987-06-16 | 1987-12-16 | $7700.00 | Window Closed / Lapsed |