Patent US3812924A successfully refreshed from Google Patents.
US3812924A
Expired / Lapsed
US
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Device for monitoring a change in mass in varying gravimetric environments
Assignee: National Aeronautics and Space Administration
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Filing: 1973-03-13
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Granted: 1974-05-28
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Expires: 1993-03-13
Abstract
Abstract A remotely operable device for detecting changes as they occur in the mass of a selected specimen. The device is characterized by a balance beam including at one end thereof a support for receiving a specimen having a changing mass and suspension means, including a flexure, supporting the beam near its center of gravity for pivotal movement imparted thereto proportionally to changes occurring in the mass of the specimen, and strain gages coupled with the flexure for providing a read-out indicative of the pivotal movement imparted to the beam.
Inventors
- 👤 J Fletcher
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 10:22
CPC Classifications
G; G01; G01G; G01G1/00; G01G1/18; G01G3/00; G01G3/12; G01G3/14; G01G3/1402
Claims Analysis
Total Claims: 4
Claim 1
Independent Claim
247 words
A device for monitoring changes as they occur in the mass of a selected specimen comprising: an elongated balance beam including means for supporting at one end thereof a specimen having a constantly changing mass, and means for supporting a fixed mass at the opposite end thereof; said balance beam defining an open truss structure comprising a plurality of rods and an anchor plate, said rods being spaced from each other at said anchor plate and converging in one direction toward said specimen supporting means and in the other direction toward said fixed mass supporting means; the distance between said anchor plate and said specimen supporting means being substantially greater than the distance between said anchor plate and said mass supporting means; suspension means including a flexure depending from an elevated support supporting the balance beam for pivotal motion imparted thereto in response to the changing mass of said specimen, said flexure being rigidly affixed at its opposite ends to said elevated support and to said anchor plate whereby the flexure is stressed proportionately with respect to pivotal motion imparted to said beam; said flexure comprising a central portion of reduced thickness between said anchor plate and said elevated support; means for measuring the stress of said flexure comprising a plurality of strain gages affixed to said central portion of said flexure; said fixed mass supporting means comprising a screw-threaded shaft coaxially aligned with the longitudinal axis of symmetry of said beam and threadedly engaging said mass.
Claim 2
Independent Claim
247 words
A device for monitoring changes as they occur in the mass of a selected specimen comprising: an elongated balance beam including means for supporting at one end thereof a specimen having a constantly changing mass, and means for supporting a fixed mass at the opposite end thereof; said balance beam defining an open truss structure comprising a plurality of rods and an anchor plate, said rods being spaced from each other at said anchor plate and converging in one direction toward said specimen supporting means and in the other direction toward said fixed mass supporting means; the distance between said anchor plate and said specimen supporting means being substantially greater than the distance between said anchor plate and said mass supporting means; suspension means including a flexure depending from an elevated support supporting the balance beam for pivotal motion imparted thereto in response to the changing mass of said specimen, said flexure being rigidly affixed at its opposite ends to said elevated support and to said anchor plate whereby the flexure is stressed proportionately with respect to pivotal motion imparted to said beam; said flexure comprising a central portion of reduced thickness between said anchor plate and said elevated support; means for measuring the stress of said flexure comprising a plurality of strain gages affixed to said central portion of said flexure; said fixed mass supporting means comprising a screw-threaded shaft coaxially aligned with the longitudinal axis of symmetry of said beam and threadedly engaging said mass.
Claim 3
Dependent Claim
30 words
The invention as defined in claim 1 including a fluid-containing dash pot supported beneath said balance beam, a pressure plate disposed in said dash pot and coupled to said beam.
Claim 4
Dependent Claim
26 words
The invention as defined in claim 1 wherein said specimen supporting means is spaced substantially six times further from said anchor plate than is said mass.
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) | 1977-05-27 | 1977-11-26 | 1978-05-28 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-05-27 | 1981-11-26 | 1982-05-28 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-05-27 | 1985-11-26 | 1986-05-28 | $7700.00 | Window Closed / Lapsed |