Patent US2925748A successfully refreshed from Google Patents.
US4075762A
Expired / Lapsed
US
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Instrument for making perspective drawing
Assignee: Individual
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Filing: 1976-09-28
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Granted: 1978-02-28
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Expires: 1996-09-28
Abstract
Abstract An instrument adapted for making perspective drawing, comprising a slider on a base plate and a link pivoted to two levers of exactly equal lengths between pivot centers and at equal distances on the slider and the link. The arrangement further includes a ruler or bar extending in a direction generally transversely to the levers and connected thereto by means of a joint structure which is slidable along the levers to any desired set position and which permits a rotational as well as a sliding motion of the ruler relative to the joint center as the angular position of the ruler relative to the levers is changed.
Inventors
- 👤 Kazuomi Ohtake
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 22:42
CPC Classifications
B; B43; B43L; B43L13/00; B43L13/14; B43L13/141
Claims Analysis
Total Claims: 4
Claim 1
Independent Claim
174 words
An instrument for making perspective drawings comprising a base plate to be located on a drawing board, a slider, means mounting said slider on said base plate for rectilinear sliding movement thereon, means for clamping said slider to said base plate in any desired position therealong, a parallelogram lever-and-link arrangement comprising a pair of parallel levers pivotally mounted at one end thereof on said slider and a link extending between and pivotally connected to the opposite ends of said levers, a ruler, and a pair of joint structures respectively interconnecting said ruler with said levers, each said joint structure including a sleeve establishing a sliding fit on said lever together with means for releasably fastening them together, a bracket pivotally mounted on said sleeve, and shoe means carried by said bracket, said ruler being provided with a longitudinally extending slotted portion with which said shoe means are engaged for slidingly guiding longitudinal movement of said ruler, and means for clamping said shoe means to said slotted portion at any desired position along said ruler.
Claim 2
Dependent Claim
174 words
An instrument for making perspective drawings comprising a base plate to be located on a drawing board, a slider, means mounting said slider on said base plate for rectilinear sliding movement thereon, means for clamping said slider to said base plate in any desired position therealong, a parallelogram lever-and-link arrangement comprising a pair of parallel levers pivotally mounted at one end thereof on said slider and a link extending between and pivotally connected to the opposite ends of said levers, a ruler, and a pair of joint structures respectively interconnecting said ruler with said levers, each said joint structure including a sleeve establishing a sliding fit on said lever together with means for releasably fastening them together, a bracket pivotally mounted on said sleeve, and shoe means carried by said bracket, said ruler being provided with a longitudinally extending slotted portion with which said shoe means are engaged for slidingly guiding longitudinal movement of said ruler, and means for clamping said shoe means to said slotted portion at any desired position along said ruler.
Claim 3
Dependent Claim
73 words
An instrument as defined in claim 1 for making perspective drawings wherein said means for mounting said slider on said base plate includes a longitudinally extending guide slot in said base plate and shoe means on said slider slidingly engaged within said guide slot, and wherein said means for clamping said slider to said base plate includes a clamping screw carried by said slider and engageable with the surface of said guide slot.
Claim 4
Dependent Claim
97 words
An instrument as defined in claim 2 for making perspective drawings wherein said guide slot in said base plate has an inverted T-shaped configuration and said clamping screw includes a bottom head, a stem uprising from said bottom head and a top head, said bottom head being nested within and slidably engaged with said guide slot, said stem being threaded and protruding outwardly and upwardly from said guide slot and through said slider, and said top head being a nut screwable onto said stem for clamping between it and said bottom head said slider and base plate.
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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) | 1981-02-27 | 1981-08-29 | 1982-02-28 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1985-02-27 | 1985-08-29 | 1986-02-28 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1989-02-27 | 1989-08-29 | 1990-02-28 | $7700.00 | Window Closed / Lapsed |