DRAFTSMAN'S INSTRUMENT Russian patent published in 2004 - IPC

FIELD: draftsman's and marking instruments - devices for marking-out of the centers of faces of cylindrical shafts, round blanks and arcs of circumferences with an unknown center. SUBSTANCE: the draftsman's instrument includes components simulating the tangents to the circumference located at an angle to one another, and the bisector of the mentioned angle. The simulator of tangents is made in the form of a cramp with a triangular prismatic cut-out, and the simulator of the bisector - in the form of a plate placed along the bisector of the angle of the prismatic cut-out asymmetrically relative to the cramp planes and flush with one of them. The plate ha a longitudinal groove for placement of the marking tool or pencil in it. EFFECT: simplified construction, enhanced precision of marking-out and serves as universal multi-purpose instrument. 1 dwg