US3915015A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Strain gauge transducer system
Assignee: SRI International Inc
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Filing: 1974-03-18
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Granted: 1975-10-28
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Expires: 1994-03-18
Abstract
Abstract A writing instrument is provided which generates electrical signals indicative of the force applied and the direction of motion taken by the writing instrument as one is writing with it. The writing instrument uses strain gauges for providing these signals.
Inventors
- 👤 Hewitt D Crane
- 👤 Jon C Taenzer
- 👤 Gerry B Andeen
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 12:35
CPC Classifications
B; B43; B43K; B43K29/00; B43K29/08; G; G01; G01L; G01L1/00; G01L1/20; G01L1/22; G01L5/00; G01L5/16; G01L5/161; G01L5/162; G01L5/1627; G01L9/00; G01L9/02; G01L9/04; G01P; G01P13/00; G01P13/02; G01P5/00; G01P5/02; G06; G06F; G06F3/00; G06F3/01; G06F3/03; G06F3/033; G06F3/0354; G06F3/03545
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
262 words
Apparatus for generating signals representative of the force on and direction of motion of one end of a shaft comprising flexible diaphragm means, means for supporting said flexible diaphragm means at its periphery, means for attaching said shaft to said flexible diaphragm means at a location spaced from said one end to cause strain within said diaphragm responsive to force on and motion of said one end of said shaft, a plurality of strain gauge means attached to at least one surface of said flexible diaphragm means and disposed around the location on said flexible diaphragm to which said shaft is attached for generating signals representative of the strains within said diaphragm, and circuit means for combining said strain gauge means signals for producing signals representative of the forces on and direction of motion of said one end of said shaft, including a bridge circuit including means for combining output signals from strain gauges which lie along a first line passing through said location on said diaphragm for producing a resultant signal representative of the force on one end of said shaft along one axis, means for combining output signals from strain gauges which lie along a second line intersecting at right angles with said first line at said location on said diaphragm for producing a resultant signal representative of the force on said one end of said shaft along a second axis, and means for combining all of the signals from said strain gauges for producing an output signal representative of the axial force on said one end of said rod.
Claim 2
Dependent Claim
262 words
Apparatus for generating signals representative of the force on and direction of motion of one end of a shaft comprising flexible diaphragm means, means for supporting said flexible diaphragm means at its periphery, means for attaching said shaft to said flexible diaphragm means at a location spaced from said one end to cause strain within said diaphragm responsive to force on and motion of said one end of said shaft, a plurality of strain gauge means attached to at least one surface of said flexible diaphragm means and disposed around the location on said flexible diaphragm to which said shaft is attached for generating signals representative of the strains within said diaphragm, and circuit means for combining said strain gauge means signals for producing signals representative of the forces on and direction of motion of said one end of said shaft, including a bridge circuit including means for combining output signals from strain gauges which lie along a first line passing through said location on said diaphragm for producing a resultant signal representative of the force on one end of said shaft along one axis, means for combining output signals from strain gauges which lie along a second line intersecting at right angles with said first line at said location on said diaphragm for producing a resultant signal representative of the force on said one end of said shaft along a second axis, and means for combining all of the signals from said strain gauges for producing an output signal representative of the axial force on said one end of said rod.
Claim 3
Dependent Claim
151 words
Apparatus for generating signals representative of the force and direction of motion of a writing instrument used for writing, comprising a shaft having writing means at one end thereof, flexible diaphragm means, means for attaching said shaft to said flexible diaphragm means at a location spaced from said one end to cause strains within said diaphragm responsive to pressure on and motion of said writing means, means for supporting said diaphragm by its periphery with said writing means extending from one end thereof, a plurality of strain gauge means attached to at least one surface of said flexible diaphragm means and disposed around the location on said flexible diaphragm to which said shaft is attached for generating signals representative of the strains within said diaphragm, and circuit means for combining said strain gauge means signals for producing signals representative of the force on and direction of motion of said writing means.
Claim 4
Dependent Claim
151 words
Apparatus for generating signals representative of the force and direction of motion of a writing instrument used for writing, comprising a shaft having writing means at one end thereof, flexible diaphragm means, means for attaching said shaft to said flexible diaphragm means at a location spaced from said one end to cause strains within said diaphragm responsive to pressure on and motion of said writing means, means for supporting said diaphragm by its periphery with said writing means extending from one end thereof, a plurality of strain gauge means attached to at least one surface of said flexible diaphragm means and disposed around the location on said flexible diaphragm to which said shaft is attached for generating signals representative of the strains within said diaphragm, and circuit means for combining said strain gauge means signals for producing signals representative of the force on and direction of motion of said writing means.
Claim 5
Dependent Claim
133 words
Apparatus as recited in claim 2 wherein said plurality of strain gauge means comprise eight strain gauges two of which are positioned on one surface of said flexible diaphragm means on opposite sides of the location to which said shaft is attached and on a first line passing therethrough, another two of said strain gauges are positioned on said one surface of said flexible diaphragm means on opposite sides of the location to which said shaft is attached and on a line passing therethrough and at a right angle to said first line, and the remaining four of said eight strain gauges being attached to the surface opposite said one surface of said flexible diaphragm means and opposite to the location to which said first four of said eight strain gauges are attached.
Claim 6
Dependent Claim
93 words
Apparatus as recited in claim 2 wherein said plurality of strain gauge means comprises eight strain gauges all of which are attached to one surface of said diaphragm, a first four of which are positioned symmetrically on either side of the location to which said shaft is attached and along a first line passing therethrough, and the remaining four of said strain gauges being positioned symmetrically on either side of the location to which said shaft is attached and along a second line which passes therethrough and is orthogonal to said first line.
Claim 7
Dependent Claim
40 words
Apparatus for generating signal as recited in claim 2 wherein said plurality of strain gauge means comprises four strain gauges attached to one surface of said flexible diaphragm means and symmetrically disposed about said location which said shaft is attached.
Claim 8
Dependent Claim
52 words
Apparatus for generating signals as recited in claim 2 wherein said plurality of strain gauge means comprises four strain gauges, a first two of which are attached to one surface of said flexible diaphragm means, and a second two of which are attached to the opposite surface of said flexible diaphragm means.
Claim 9
Dependent Claim
135 words
Apparatus as recited in claim 2 wherein said circuit means comprises a bridge circuit including means for combining output signals from strain gauges which lie along a first line passing through said location on said diaphragm for producing a resultant signal representative of the direction of motion of one end of said shaft along one axis, means for combining output signals from said gauges which lie along a second line intersecting at right angles with said first line at said location on said diaphragm for producing a resultant signal representative of the direction of motion of said one end of said shaft along a second axis, and means for combining all of the signals from said strain gauges for producing an output signal representative of the axial motion of said one end of said shaft.
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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) | 1978-10-27 | 1979-04-28 | 1979-10-28 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-10-27 | 1983-04-28 | 1983-10-28 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-10-27 | 1987-04-28 | 1987-10-28 | $7700.00 | Window Closed / Lapsed |