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Patent US3835298A successfully refreshed from Google Patents.
US3835298A
Expired / Lapsed
US
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Device for demonstrating and calculating mathematical functions
Assignee: ANDREA J DE
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Filing: 1973-08-15
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Granted: 1974-09-10
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Expires: 1993-08-15
Abstract
Abstract A device for demonstrating and calculating mathemetical functions comprising a planar member having a unit circle inscribed thereon and a 90* angular scale associated therewith to indicate the angle of an arc measured within one quadrant of the unit circle. The planar member also includes perpendicularly extending ordinate and abscissa axes positioned with their point of intersection at the origin of the unit circle. Numerical indicia are associated with each axis to indicate sine, cosine, versine and coversine values. A cursor member carrying a radius vector hairline inscribed thereon is pivotally mounted within the open interior of the planar member at the origin of the unit circle with the radius vector hairline passing through the origin. A flat, transparent indicator member having two intersecting perpendicular hairlines inscribed thereon is pivotally mounted within the interior portion of the planar member to the cursor member. Alignment means is provided to maintain a perpendicular relationship between the hairlines of the indicator member with the abscissa and ordinate axes when said cursor member and flat indicator member are moved through a quadrant of the unit circle thus permitting visual observation of the sine and cosine values of an inscribed angle at the points of intersection of the pair of perpendicular hairlines with the ordinate and abscissa axes respectively. My device may also include segmental central angle indicia, arc indicia and chord indicia whereby the segmental central angle of any inscribed angle within a quadrant of the unit circle may be determined along with the length of arc and length of chord for said segmental central angle.
Inventors
- 👤 Andrea J De
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-06 15:58
CPC Classifications
G; G06; G06G; G06G1/00; G06G1/02; G06G1/10
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
387 words
A device for demonstrating and calculating mathematical functions comprising: a. A flat planar member including upper and lower surfaces disposed on opposite flat faces thereof, said planar member having an open interior portion between said surfaces and including a unit circle disposed on the upper surface with ordinate and abscissa axes positioned on said circle extending perpendicularly from the origin of said circle, said ordinate and abscissa axes having numerical indicia associated therewith, linearly calibrated from 0 at the origin of the unit circle to 1 at its perimeter, said distance defining one unit length, said planar member also including an angular scale to indicate the inscribed angle of an arc within a first 90* quadrant of the unit circle the interior portion of said planar member being visually observable within said first quadrant, said planar member also having a pair of alignment tracks formed on the interior side of the upper surface, said alignment tracks formed to describe 90* arcs of the unit circle and positioned in spaced apart relationship each passing through diagonally opposite quadrants adjacent said first quadrant; b. a cursor member having a radius vector hairline of at least one unit length inscribed thereon, said cursor pivotally mounted within the open interior portion of the planar member at the origin of the unit circle with the radius vector hairline passing through said origin; c. a flat, transparent indicator member having two intersecting perpendicular hairlines of at least one unit length inscribed thereon, said indicator member pivotally mounted to the radius vector hairline of the cursor member, one unit length from the origin of said circle at the point of intersection of the two perpendicular hairlines, said indicator member positioned between said cursor member and the upper surface of the planar member, said indicator member also including a pair of alignment pins attached thereto and upwardly extending therefrom, each of said pins slidably positioned within one of said alignment tracks, whereby said pair of hairlines remain perpendicular to the ordinate and abscissa axes respectively when said cursor member and flat indicator member are moved through the first quadrant of said unit circle to permit vessel observation of the sine and cosine values of an inscribed angle at the points of intersection of the pair of perpendicular hairlines with the ordinate and abscissa axes respectively.
Claim 2
Independent Claim
387 words
A device for demonstrating and calculating mathematical functions comprising: a. A flat planar member including upper and lower surfaces disposed on opposite flat faces thereof, said planar member having an open interior portion between said surfaces and including a unit circle disposed on the upper surface with ordinate and abscissa axes positioned on said circle extending perpendicularly from the origin of said circle, said ordinate and abscissa axes having numerical indicia associated therewith, linearly calibrated from 0 at the origin of the unit circle to 1 at its perimeter, said distance defining one unit length, said planar member also including an angular scale to indicate the inscribed angle of an arc within a first 90* quadrant of the unit circle the interior portion of said planar member being visually observable within said first quadrant, said planar member also having a pair of alignment tracks formed on the interior side of the upper surface, said alignment tracks formed to describe 90* arcs of the unit circle and positioned in spaced apart relationship each passing through diagonally opposite quadrants adjacent said first quadrant; b. a cursor member having a radius vector hairline of at least one unit length inscribed thereon, said cursor pivotally mounted within the open interior portion of the planar member at the origin of the unit circle with the radius vector hairline passing through said origin; c. a flat, transparent indicator member having two intersecting perpendicular hairlines of at least one unit length inscribed thereon, said indicator member pivotally mounted to the radius vector hairline of the cursor member, one unit length from the origin of said circle at the point of intersection of the two perpendicular hairlines, said indicator member positioned between said cursor member and the upper surface of the planar member, said indicator member also including a pair of alignment pins attached thereto and upwardly extending therefrom, each of said pins slidably positioned within one of said alignment tracks, whereby said pair of hairlines remain perpendicular to the ordinate and abscissa axes respectively when said cursor member and flat indicator member are moved through the first quadrant of said unit circle to permit vessel observation of the sine and cosine values of an inscribed angle at the points of intersection of the pair of perpendicular hairlines with the ordinate and abscissa axes respectively.
Claim 3
Dependent Claim
61 words
The device of claim 1 including additional numerical indicia positioned adjacent the abscissa and ordinate axes, said indicia linearly calibrated from 1 at the origin of the circle to 0 at its perimeter to permit visual observation of coversine and versine values at the intersection of the perpendicular hairlines of the indicator member with the ordinate axis and abscissa axis respectively.
Claim 4
Dependent Claim
154 words
The device of claim 1 wherein the radius vector hairline is of a length at least as great as the diameter of the unit circle, said planar member including a segmental central angle scale positioned adjacent the perimeter of a second quadrant of the circle, said second quadrant diagonally adjacent the aforementioned first quadrant, said planar member including a cutout portion through the upper surface thereof positioned adjacent saId central angle scale to permit visual observation of the radius vector hairline therethrough, said segmental central angle scale also having numerical indicia associated therewith, said indicia linearly calibrated from 0* at the ordinate axis to 180* at the abscissa axis, whereby a segmental central angle corresponding to an angle inscribed by the radius vector hairline within the first quadrant may be determined by visual observation of the point of intersection of the radius vector hairline with the segmental central angle scale of the second quadrant.
Claim 5
Dependent Claim
41 words
The device of claim 3 including numerical indicia positioned adjacent the segmental central angle scale of the second quadrant for indicating the arc length and chord length for a plurality of segmental central angles between the values of 0* and 180*.
Claim 6
Dependent Claim
14 words
The device of claim 1 including a transparent cover positioned within said first quadrant.
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) | 1977-09-09 | 1978-03-11 | 1978-09-10 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-09-09 | 1982-03-11 | 1982-09-10 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-09-09 | 1986-03-11 | 1986-09-10 | $7700.00 | Window Closed / Lapsed |