US3221410A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Perspective drawing instrument
Assignee: Individual
•
Filing: 1963-12-09
•
Granted: 1965-12-07
•
Expires: 1983-12-09
Abstract
No abstract record available.
Inventors
- 👤 John H Malven
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 22:52
CPC Classifications
B; B43; B43L; B43L13/00; B43L13/14; B43L13/141; B43L13/142
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
182 words
AN INSTRUMENT FOR LOCATING AND DRAWING PERSPECTIVE LINES ON A DRAWING BOARD COMPRISING A DRAWING BOARD SUPPORTED BY A PEDESTAL, SAID BOARD HAVING AN UPPER DRAWING FACE, AN UPPER EDGE AND A LOWER EDGE, AND A WORKING EDGE ALONG ONE SIDE, A PERSPECTIVE HEAD SLIDEABLY SUPPORTED TO MOVE ALONG THE WORKING EDGE OF SAID DRAWING BOARD, A LEG DEPENDING FROM THE BOARD BELOW THE WORKING EDGE, A LEVER CONNECTED WITH SAID PERSPECTIVE HEAD AND PIN MEANS SLIDABLY CONNECTING SAID LEG AND SAID LEVER AT THEIR DISTAL ENDS, A RULER HEAD HAVING A RULER EXTENDING ACROSS SAID DRAWING BOARD AND HELD AT ONE END BY SAID RULER HEAD, A PERSPECTIVE SHAFT CONNECTING THE PERSPECTIVE HEAD WITH THE RULER HEAD, SAID SHAFT HAVING A FLATTENED PIVOTALLY HELD OUTER END AND A BALL AT THE INNER END CONNECTED TO SAID RULER HEAD BY A SOCKET THEREIN, MEANS FOR ADJUSTMENT OF THE ANGLE THAT SAID SHAFT MAINTAINS RELATIVE TO THE VERTICAL IN SAID PERSPECTIVE HEAD SO THAT THE ANGLE OF SAID PERSPECTIVE SHAFT MAY BE VARIED WITH REFERENCE TO THE VERTICAL POSITION OF SAID PERSPECTIVE HEAD.
Claim 2
Dependent Claim
182 words
AN INSTRUMENT FOR LOCATING AND DRAWING PERSPECTIVE LINES ON A DRAWING BOARD COMPRISING A DRAWING BOARD SUPPORTED BY A PEDESTAL, SAID BOARD HAVING AN UPPER DRAWING FACE, AN UPPER EDGE AND A LOWER EDGE, AND A WORKING EDGE ALONG ONE SIDE, A PERSPECTIVE HEAD SLIDEABLY SUPPORTED TO MOVE ALONG THE WORKING EDGE OF SAID DRAWING BOARD, A LEG DEPENDING FROM THE BOARD BELOW THE WORKING EDGE, A LEVER CONNECTED WITH SAID PERSPECTIVE HEAD AND PIN MEANS SLIDABLY CONNECTING SAID LEG AND SAID LEVER AT THEIR DISTAL ENDS, A RULER HEAD HAVING A RULER EXTENDING ACROSS SAID DRAWING BOARD AND HELD AT ONE END BY SAID RULER HEAD, A PERSPECTIVE SHAFT CONNECTING THE PERSPECTIVE HEAD WITH THE RULER HEAD, SAID SHAFT HAVING A FLATTENED PIVOTALLY HELD OUTER END AND A BALL AT THE INNER END CONNECTED TO SAID RULER HEAD BY A SOCKET THEREIN, MEANS FOR ADJUSTMENT OF THE ANGLE THAT SAID SHAFT MAINTAINS RELATIVE TO THE VERTICAL IN SAID PERSPECTIVE HEAD SO THAT THE ANGLE OF SAID PERSPECTIVE SHAFT MAY BE VARIED WITH REFERENCE TO THE VERTICAL POSITION OF SAID PERSPECTIVE HEAD.
References Cited (Backward Citations)
AT59735B
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1968-12-06 | 1969-06-07 | 1969-12-07 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1972-12-06 | 1973-06-07 | 1973-12-07 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1976-12-06 | 1977-06-07 | 1977-12-07 | $7700.00 | Window Closed / Lapsed |