Vari-scale

摘要

This invention relates to a graduated engineer/architect rule having variably selectable scales for measuring distances and establishing linear proportionalities for representation on a technical drawing. The rule comprises an enclosed, continuous fabric sheet bearing a plurality of divided scales of both the engineer and architect type. The sheet is mounted on and carried by idler rollers, guide platens, and a full length drive platen. A specific scale may be selected by rotating a scale adjustment knob to rotate the drive platen and advance the sheet adjacent to a full length viewing window.