APPARATUS FOR DRAFTING AN EXACT AXONOMETRIC PROJECTION DIRECTLY FROM A MULTIVIEW ORTHOGRAPHIC PROJECTION

摘要

An apparatus mounted on a drafting board for drafting an exact axonometric projection of an object directly from a multiview orthographic projection of such object. The apparatus includes at least two reference devices placed on the drafting board each adapted to be positioned along a running line extending from corresponding points of at least two views placed in their normal orientation in orthographic projection of such object and oriented at a predetermined angle from a reference in the direction of sight, and a tracing device associated with each reference device and defining an axonometric line oriented at an angle from such reference depending upon the desired angles of the axonometric projection. The intersection the axonometric lines derived from said two views in orthographic projection defines one point of the axonometric projection. There is also provided a guide member also placed on the drafting board and positioned along a directrix line perpendicular to the bisectrix of the angle formed by each reference and tracing devices for guiding the reference and tracing devices whereby movement of each reference device to positions corresponding to other corresponding points of such object in the multiview orthographic projection will define the corresponding points in the axonometric projection at the intersection of the tracing devices. In an alternative embodiment, the reference and tracing devices could be the same device pivotably mounted on supporting arm to oscillate between a reference position corresponding to a running line to a tracing position corresponding to an exometric line. The supporting arm is perpendicular to the guide member.