US4586265A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Perspective drawing apparatus
Assignee: HOPKINS WILLIAM GEORGE
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Filing: 1984-10-29
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Granted: 1986-05-06
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Expires: 2004-10-29
Abstract
Abstract A drafting apparatus having a linear edge with first and second wheel means associated with the edge to rotatably move the linear edge across a planar drafting surface and wherein the wheels are of differing diameter so as to have the linear edge move across an arc defined within a circle toward which the linear edge is always pointed. The center of that circle is the vanishing point as conventionally utilized with perspective drawing techniques.
Inventors
- 👤 William G. Hopkins
- 👤 Philip L. Reid
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 22:46
CPC Classifications
B; B43; B43L; B43L13/00; B43L13/14; B43L13/141; B43L13/145; B43L7/00; B43L7/04
Claims Analysis
Total Claims: 4
Claim 1
Independent Claim
93 words
A drafting apparatus for use in producing a perspective drawing, comprising: a rule defining two parallel linear edges and defining in a central portion thereof a slot; an axle mounted in said slot; first wheel means mounted on said axle; second wheel means mounted on said axle; and wherein said first wheel means is of a greater diameter than said second wheel means whereby when said apparatus is rotably moved across a planar surface, said apparatus moves in an arc about a circle toward which one of said linear edges is always directed.
Claim 2
Dependent Claim
93 words
A drafting apparatus for use in producing a perspective drawing, comprising: a rule defining two parallel linear edges and defining in a central portion thereof a slot; an axle mounted in said slot; first wheel means mounted on said axle; second wheel means mounted on said axle; and wherein said first wheel means is of a greater diameter than said second wheel means whereby when said apparatus is rotably moved across a planar surface, said apparatus moves in an arc about a circle toward which one of said linear edges is always directed.
Claim 3
Independent Claim
63 words
An apparatus for producing perspective drawings comprising: rule means defining a pair of parallel linear edges and defining within the central portion thereof a slot; a tapered dowel mounted within said slot in a different plane from said linear edges whereby the surface of said tapered dowel when on a planar surface is substantially parallel to said linear edge along said planar surface.
Claim 4
Independent Claim
63 words
An apparatus for producing perspective drawings comprising: rule means defining a pair of parallel linear edges and defining within the central portion thereof a slot; a tapered dowel mounted within said slot in a different plane from said linear edges whereby the surface of said tapered dowel when on a planar surface is substantially parallel to said linear edge along said planar surface.
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) | 1989-05-05 | 1989-11-04 | 1990-05-06 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1993-05-05 | 1993-11-04 | 1994-05-06 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1997-05-05 | 1997-11-04 | 1998-05-06 | $7700.00 | Window Closed / Lapsed |