Patent US3933032A successfully refreshed from Google Patents.
US3933032A
Expired / Lapsed
US
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Dynamic rheometer
Assignee: California Institute of Technology
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Filing: 1971-09-01
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Granted: 1976-01-20
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Expires: 1991-09-01
Abstract
Abstract The dynamic mechanical properties of polymeric materials can be measured either in uniaxial compression or in flexure as a function of frequency over a wide frequency as well as temperature range, by using a piezoelectric driver to apply a displacement to a sample and a piezoelectric pickup to pick up the forces transmitted through the sample together with electrical circuitry whereby the amplitude ratio and phase angle between drive and pickup signals may be read.
Inventors
- 👤 Nicholas W. Tschoegl
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 09:28
CPC Classifications
G; G01; G01N; G01N29/00; G01N29/04; G01N29/07; G01N29/11; G01N29/22; G01N29/227; G01N3/00; G01N3/32; G01N3/38; G01N2203/00; G01N2203/003; G01N2203/005; G01N2203/0051; G01N2203/02; G01N2203/022; G01N2203/0222; G01N2291/00; G01N2291/02; G01N2291/023; G01N2291/0235
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
114 words
A dynamic rheometer comprising: a support base, a piezoelectric transducer means supported on said support base, means for supporting a specimen to be tested on said piezoelectric transducer means, a force pickup transducer, means for supporting said force pickup transducer on top of said specimen to be tested for generating signals responsive to motion of said specimen, power means for driving said piezoelectric transducer means for causing compression deflections and flexure deflections to said specimen, and means for comparing the phase and amplitude of the signals applied by said power means to said piezoelectric transducer means and the signals generated by said force pickup means in response to compression and deflection of said specimen.
Claim 2
Dependent Claim
114 words
A dynamic rheometer comprising: a support base, a piezoelectric transducer means supported on said support base, means for supporting a specimen to be tested on said piezoelectric transducer means, a force pickup transducer, means for supporting said force pickup transducer on top of said specimen to be tested for generating signals responsive to motion of said specimen, power means for driving said piezoelectric transducer means for causing compression deflections and flexure deflections to said specimen, and means for comparing the phase and amplitude of the signals applied by said power means to said piezoelectric transducer means and the signals generated by said force pickup means in response to compression and deflection of said specimen.
Claim 3
Dependent Claim
36 words
A dynamic rheometer as recited in claim 1 wherein said piezoelectric transducer includes a stack of piezoelectric discs and said support base includes wall means for elastically enclosing the sides of said stack of piezoelectric discs.
Claim 4
Dependent Claim
28 words
A dynamic rheometer as recited in claim 1 wherein said piezoelectric transducer means is a stack of piezoelectric discs, and said force pickup transducer is a piezoelectric cylinder.
Claim 5
Dependent Claim
73 words
A dynamic rheometer as recited in claim 2 wherein there is included a top plate on said stack of piezoelectric discs having two upstanding wedge-shaped members for supporting a specimen for testing in flexure, and said force pickup transducer has a plate thereon with a wedge-shaped member positioned to contact said specimen midway between said two upstanding wedge-shaped members and on the side opposite to the one supported by said two wedge-shaped members.
Claim 6
Dependent Claim
64 words
A dynamic rheometer as recited in claim 1 wherein said means for supporting said force pickup transducer on said specimen to be tested includes a support block having said force pickup transducer attached to one end thereof, and micrometer means coupled to the other end of said support block for positioning said support block and said force pickup transducer means at a desired location.
Claim 7
Dependent Claim
58 words
A dynamic rheometer as recited in claim 5 wherein there is included housing means having an opening therein, wherein said piezoelectric transducer means, said specimen, said force pickup transducer means and said means for supporting said force pickup transducer means are supported, and means supported by said housing means for clamping said micrometer means at a desired location.
Claim 8
Independent Claim
178 words
A system for measuring the dynamic mechanical properties of material in either compression or in flexure as a function of frequency comprising a dynamic rheometer including: a support base, a stack of piezoelectric discs mounted on said support base, means for supporting a specimen to be tested on said stack of piezoelectric discs, a cylindrical piezoelectric force pick up transducer, means for supporting said cylindrical piezoelectric force pick up transducer on said specimen to be tested, with its cylindrical axis normal to the plane established by said specimen to be tested, a source of signals having a desired frequency and amplitude, means for applying signals from said source to said stack of piezoelectric discs for applying flexure deflections and compression deflections to said specimen, means for measuring the phase angle and amplitude ratio between the signals applied to said stack of piezoelectric discs and signals generated by said cylindrical force pickup transducer responsive to deformations of said specimen, and means for applying signals from said source and from said cylindrical piezoelectric force pickup to said means for measuring.
Claim 9
Independent Claim
178 words
A system for measuring the dynamic mechanical properties of material in either compression or in flexure as a function of frequency comprising a dynamic rheometer including: a support base, a stack of piezoelectric discs mounted on said support base, means for supporting a specimen to be tested on said stack of piezoelectric discs, a cylindrical piezoelectric force pick up transducer, means for supporting said cylindrical piezoelectric force pick up transducer on said specimen to be tested, with its cylindrical axis normal to the plane established by said specimen to be tested, a source of signals having a desired frequency and amplitude, means for applying signals from said source to said stack of piezoelectric discs for applying flexure deflections and compression deflections to said specimen, means for measuring the phase angle and amplitude ratio between the signals applied to said stack of piezoelectric discs and signals generated by said cylindrical force pickup transducer responsive to deformations of said specimen, and means for applying signals from said source and from said cylindrical piezoelectric force pickup to said means for measuring.
Claim 10
Dependent Claim
56 words
A dynamic rheometer as recited in claim 7 wherein said support base includes wall means for elastically enclosing the sides of said stack of piezoelectric discs, said means for supporting a specimen to be tested on said stack of piezoelectric discs includes a plate on said elastic walled housing means on which said specimen is placed.
Claim 11
Dependent Claim
65 words
A dynamic rheometer as recited in claim 7 wherein said plate has a pair of spaced upstanding wedge-shaped members for supporting a specimen for testing in flexure, and said force pick up transducer has a plate thereon with a wedge-shaped member positioned to contact said specimen midway between said two upstanding wedge-shaped members on the side to the one supported by said two wedge-shaped members.
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) | 1979-01-19 | 1979-07-21 | 1980-01-20 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1983-01-19 | 1983-07-21 | 1984-01-20 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1987-01-19 | 1987-07-21 | 1988-01-20 | $7700.00 | Window Closed / Lapsed |