Patent US3576128A successfully refreshed from Google Patents.
US3576128A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Half bridge moment desensitization of parallelogram-type beams
Assignee: BLH Electronics Inc
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Filing: 1969-03-13
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Granted: 1971-04-27
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Expires: 1989-03-13
Abstract
Abstract A rigid-ended multiple bending parallelogram-type beam which includes a plurality of electrical strain gauge elements mounted thereon is moment desensitized by the application of a pair of shunting resistors across a half of a bridge circuit arrangement formed by the strain gauge elements whereby accurate force measurements independent of load position may be realized.
Inventors
- 👤 Harry E Lockery
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 11:24
CPC Classifications
G; G01; G01L; G01L1/00; G01L1/20; G01L1/22; G01L1/2206; G01L1/2243; G01L1/225; G01L1/2262
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
239 words
Force measuring apparatus comprising a relatively fixed support, force-responsive means, and at least one structural transducer means providing substantially the sole mechanical mounting for said force-responsive means in relation to said support, said structural transducer means comprising a pair of spaced substantially parallel beam elements of material having high elasticity, means rigidly interconnecting the adjacent ends of said beam elements together and to said force-responsive means, means rigidly interconnecting the opposite ends of said beam elements together and to said support, a plurality of electrical strain gauge means mounted substantially on the most strain sensitive portions of said parallel beam elements, said strain gauge means being essentially responsive only to stresses characterizing the magnitudes of forces applied to said structural transducer means by said force-responsive means in a direction perpendicular to said beam elements in substantially the same plane therewith, said structural transducer means limiting deflections of said force-responsive means relative to said support to substantially said direction, said plurality of eLectrical strain gauge means including at least two electrical resistance strain gauges connected to surfaces of each of said beam elements at the different end strain sensitive portions thereof, and shunt resistance means including at least two resistors connected in parallel across two of said strain gauges located on opposite beam elements at the same end of said structural transducer means and having resistance which counters errors in force measurement caused by moment sensitivity of said transducer means.
Claim 2
Dependent Claim
239 words
Force measuring apparatus comprising a relatively fixed support, force-responsive means, and at least one structural transducer means providing substantially the sole mechanical mounting for said force-responsive means in relation to said support, said structural transducer means comprising a pair of spaced substantially parallel beam elements of material having high elasticity, means rigidly interconnecting the adjacent ends of said beam elements together and to said force-responsive means, means rigidly interconnecting the opposite ends of said beam elements together and to said support, a plurality of electrical strain gauge means mounted substantially on the most strain sensitive portions of said parallel beam elements, said strain gauge means being essentially responsive only to stresses characterizing the magnitudes of forces applied to said structural transducer means by said force-responsive means in a direction perpendicular to said beam elements in substantially the same plane therewith, said structural transducer means limiting deflections of said force-responsive means relative to said support to substantially said direction, said plurality of eLectrical strain gauge means including at least two electrical resistance strain gauges connected to surfaces of each of said beam elements at the different end strain sensitive portions thereof, and shunt resistance means including at least two resistors connected in parallel across two of said strain gauges located on opposite beam elements at the same end of said structural transducer means and having resistance which counters errors in force measurement caused by moment sensitivity of said transducer means.
Claim 3
Dependent Claim
31 words
Force measuring apparatus as in claim 1 wherein said strain gauges are connected in a bridge circuit arrangement with half of the bridge circuit arrangement including said shunt resistors connected thereacross.
Claim 4
Dependent Claim
47 words
Force measuring apparatus as in claim 2 wherein the half of said bridge circuit arrangement which includes said shunt resistors is that half which would cause the greatest change in electrical output from said bridge arrangement for a given moment change in the absence of said resistors.
Claim 5
Dependent Claim
78 words
Force measuring apparatus as in claim 3 wherein the value of said shunt resistors is of a much greater value than that of the resistance of the strain gauges across which they are connected, the value of said shunt resistors being that which causes a minimum output change to result in the electrical output of said bridge circuit arrangement for a given change in location of a force applied to said beam elements and in moment resulting therefrom.
Claim 6
Dependent Claim
17 words
Force measuring apparatus as in claim 4 wherein said bridge circuit arrangement is of the Wheatstone type.
Claim 7
Dependent Claim
222 words
Force measuring apparatus comprising a substantially rigid weighing platform, relatively fixed support means and a plurality of beam transducive sensing elements providing the sole mechanical mounting for said platform in relation to said support means, each of said beam transducive sensing elements being alike and comprising a pair of like substantially horizontal parallel beam elements of material having a high modulus of elasticity and having their adjacent ends united one above the other by substantially rigid interconnecting portions, means securing one of the interconnected ends of each of said sensing elements to said support means, means securing the other of the interconnected ends of each of said sensing elements to said platform with said platform disposed substantially horizontally above said beam transducive sensing elements, and four electrical resistance strain gauges associated with each of said beam transducive sensing elements, each of said gauges being secured to a strain sensitive surface of said beam elements near a different one of said ends thereof, two of said gauges on the same end of each of said sensing elements having resistance means connected thereacross, means connecting said strain gauges and resistance means in a bridge arrangement wherein said resistance means causes electrical outputs from said bridge arrangement to characterize accurately the forces applied to said platform regardless of the positioning of load on said platform.
Claim 8
Dependent Claim
222 words
Force measuring apparatus comprising a substantially rigid weighing platform, relatively fixed support means and a plurality of beam transducive sensing elements providing the sole mechanical mounting for said platform in relation to said support means, each of said beam transducive sensing elements being alike and comprising a pair of like substantially horizontal parallel beam elements of material having a high modulus of elasticity and having their adjacent ends united one above the other by substantially rigid interconnecting portions, means securing one of the interconnected ends of each of said sensing elements to said support means, means securing the other of the interconnected ends of each of said sensing elements to said platform with said platform disposed substantially horizontally above said beam transducive sensing elements, and four electrical resistance strain gauges associated with each of said beam transducive sensing elements, each of said gauges being secured to a strain sensitive surface of said beam elements near a different one of said ends thereof, two of said gauges on the same end of each of said sensing elements having resistance means connected thereacross, means connecting said strain gauges and resistance means in a bridge arrangement wherein said resistance means causes electrical outputs from said bridge arrangement to characterize accurately the forces applied to said platform regardless of the positioning of load on said platform.
Claim 9
Dependent Claim
59 words
Force measuring apparatus as in claim 6 wherein said resistance means are shunt resistors which desensitize said bridge arrangement with respect to error caused by change in moment attending change in load location, and wherein said connecting means connects said strain gauges in a bridge arrangement wherein said gauges tend to characterize only the vertical loading on said platform.
Claim 10
Dependent Claim
47 words
Force measuring apparatus as in claim 7 wherein the half of said bridge circuit arrangement which includes said shunt resistors is that half which would cause the greatest change in electrical output from said bridge arrangement for a given moment change in the absence of said resistors.
Claim 11
Dependent Claim
17 words
Force measuring apparatus as in claim 8 wherein said bridge circuit arrangement is of the Wheatstone type.
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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) | 1974-04-26 | 1974-10-26 | 1975-04-27 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-04-26 | 1978-10-26 | 1979-04-27 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-04-26 | 1982-10-26 | 1983-04-27 | $7700.00 | Window Closed / Lapsed |