Drafting instrument
US4821424A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Aug 1, 1988 |
| Grant date | Apr 18, 1989 |
| Priority date | — |
| Expiry date | Aug 1, 2008 |
Classification
- Technology area (CPC B)Performing Operations; Transporting
- CPC primaryB43L7/027
- WIPO fieldOther consumer goods
- WIPO sectorOther fields
Abstract
The drafting instrument of the invention generally comprises an L-shaped integrally formed substantially planar construction having one long leg and one short leg disposed perpendicular to each other. The end of each of the legs of the instrument is inclined at an angle of 45 degrees relative to the outer edge of each leg, and the lengths of the legs of the instrument are proportioned such that complimentary 60 degree and 30 degree angles are formed between the edge of the short leg and the edge of the long leg, respectively, and a straight line intersecting the end point of each leg. The instrument includes a plurality of glide points extending outwardly from each face of the instrument to support the instrument slightly above the surface upon which it is used, and further includes a handle disposed near the intersection of the two legs of the instrument to aid in reversing the instrument from face to face during use. The handle is preferably slideably disposed in an aperture and retained therein by thin end caps, allowing the handle to slide freely through the aperture in a direction perpendicular to the plane of the instrument.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.