Perspective drawing machine
AssigneeTrigometrics, Inc.
InventorJohn G. R. Francis
Life of this patent
Estimating the term…
Abstract
A drafting table includes vertical and horizontal straight edged supports together with drive mechanisms for moving the vertical straight edge such that it will always point to a viewing point and for moving the horizontal straight edges in plural different modes. In a first mode, the two horizontal straight edges are moved such that their edges always point to respective vanishing points. In a second mode the horizontal straight edges are moved such that one continues to point to a vanishing point while the other maintains a fixed angle with respect to horizontal, and so that their edges always intersect at a point along the line of view. The drive mechanisms for the horizontal straight edge supports can be disabled, reversed or their drive ratios changed in accordance with the particular drawing being made.
Claims23
A drafting table of the type for use in the preparation of drawings by the use of at least a vertical straight edge and first and second horizontal straight edges, said table including top and bottom horizontal edges and left and right side vertical edges, and further comprising:
- vertical straight edge support means (23) for determining the horizontal position of said vertical straight edge;
- first horizontal straight edge support means (226) for determining the vertical position of said first horizontal straight edge;
- second horizontal straight edge support means (326) for determining the vertical position of said second horizontal straight edge;
- and
- horizontal straight edge control means operable in at least a first mode for moving said first and second horizontal straight edge support means such that, upon vertical movement of either of said first or second horizontal straight edges, said first horizontal straight edge is automatically controlled to always point to a first predetermined point mechanically decoupled from said first horizontal straight edge and said second horizontal straight edge is automatically controlled to always point to a second predetermined point mechanically decoupled from said second horizontal straight edge.
A drafting table of the type for use in the preparation of drawings by the use of at least a vertical straight edge and first and second horizontal straight edges, said table including top and bottom horizontal edges and left and right side vertical edges, and further comprising:
- vertical straight edge support means (23) for determining the horizontal position of said vertical straight edge;
- and
- horizontal straight edge position control means operable in at least a first mode for moving said first and second horizontal straight edges such that upon vertical movement of either of said first or second horizontal straight edges, said first horizontal straight edge is automatically controlled to always point to a first predetermined point and said second horizontal straight edge is automatically controlled to always point to a second predetermined point, said horizontal straight edge position control means comprising first means for pivotably supporting said first horizontal straight edge at two first pivot points, second means for pivotably supporting said second horizontal straight edge at two second pivot points, and gear driven means for simultaneously controlling the relative positions of all of said pivot points.
A drafting table of the type for use in the preparation of drawings by the use of at least a vertical straight edge and at least one horizontal straight edge, said table comprising:
- vertical straight edge support means (23) for determining the horizontal position of said vertical straight edge;
- horizontal straight edge support means (226) for determining the vertical position of said horizontal straight edge;
- and
- horizontal straight edge control means operable in at least a first mode for moving said horizontal straight edge support means such that, upon vertical movement of said horizontal straight edge, said horizontal straight edge is automatically controlled to always point to a predetermined point mechanically decoupled from said horizontal straight edge.
Dependencies are inferred from the claim text.