DRAWING INSTRUMENT Russian patent published in 1997 - IPC

FIELD: instrument for drawing parallel lines with predetermined interval and at predetermined angle. SUBSTANCE: drawing instrument has T-square connected with drawing board by two identical pantographs arranged on reverse side of drawing board. T-square has middle and two side rulers. Disks are pivotally connected with middle ruler for synchronous variation of distance between middle ruler and side rulers in predetermined ratio. Ratio of distances between centers of pivot joints connecting disks with middle and side rulers is in accordance with ratio of distances between middle ruler and related side ruler. EFFECT: simplified construction and enhanced reliability in operation. 3 cl, 5 dwg