US3672062A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Portable drafting device
Assignee: Keuffel and Esser Co
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Filing: 1971-03-09
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Granted: 1972-06-27
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Expires: 1991-03-09
Abstract
Abstract A lightweight drafting device comprises a ferrous board and a magnetized roller which acts as a paper holder and guide means for a drafting element. The strong magnetic attraction between the board and roller ensure a fixed relation between the paper and drafting element, and maintains parallelism between drawn lines. The device is readily transportable and is operable in any convenient attitude.
Inventors
- 👤 Allister L Baker
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 22:31
CPC Classifications
B; B43; B43L; B43L13/00; B43L13/005; Y; Y10; Y10S; Y10S33/00; Y10S33/01
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
115 words
A portable drafting device comprising, in combination: a. a drafting board member comprising a substantially flat magnetically attractable working surface; b. a magnetized cylindrical roller member in magnetic engagement with said working surface; and c. a line guide member comprising a yoke element encompassing a substantial segment of the circumferential surface of said roller member, said yoke element including bearing means engaging said roller surface at a plurality of points defining at least one roller surface area which intersects a plane which is perpendicular to said board member and contains the axis of the roller, thereby establishing two orthogonal degrees of freedom for movement of said line guide member with respect to said board member.
Claim 2
Dependent Claim
115 words
A portable drafting device comprising, in combination: a. a drafting board member comprising a substantially flat magnetically attractable working surface; b. a magnetized cylindrical roller member in magnetic engagement with said working surface; and c. a line guide member comprising a yoke element encompassing a substantial segment of the circumferential surface of said roller member, said yoke element including bearing means engaging said roller surface at a plurality of points defining at least one roller surface area which intersects a plane which is perpendicular to said board member and contains the axis of the roller, thereby establishing two orthogonal degrees of freedom for movement of said line guide member with respect to said board member.
Claim 3
Dependent Claim
43 words
A device according to claim 1 wherein said drafting board member includes an upstanding wall segment presenting abutment surface portions respectively providing bases of alignment between said board and a paper sheet overlaying said board, and between said board and said roller member.
Claim 4
Dependent Claim
38 words
A device according to claim 2 wherein said abutment surface portions present substantially parallel base lines of reference for alignment of said roller member and at least one straight edge of a sheet of paper overlaying said board.
Claim 5
Dependent Claim
38 words
A device according to claim 1 wherein said yoke element bearing means comprises a plano-concave surface having a radius of curvature equal to the radius of curvature of the curvature of the circumferential surface of said roller member.
Claim 6
Dependent Claim
35 words
A device according to claim 4 wherein said yoke element includes a substantially vertically disposed surface portion forming an abutment edge which is substantially parallel to the axis of curvature of said plano-concave bearing surface.
Claim 7
Dependent Claim
40 words
A device according to claim 1 wherein said roller member comprises a plurality of magnetized cylindrical segments axially affixed to a cylindrical body and of like circumference thereto, said magnetized segments each exhibiting a north and a south magnetic pole.
Claim 8
Dependent Claim
64 words
A device according to claim 1 wherein said drafting board member comprises a substantially rectangular rigid flat plate of ferro-metallic material, said plate having at least one straight edge and having a portion adjacent said straight edge folded back along a line parallel to said straight edge to yield an upstanding wall segment forming an acute angle with the remaining portion of said plate.
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) | 1975-06-27 | 1975-12-27 | 1976-06-27 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-06-27 | 1979-12-27 | 1980-06-27 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-06-27 | 1983-12-27 | 1984-06-27 | $7700.00 | Window Closed / Lapsed |