CIRCUMFERENTIAL CIRCLE CENTER RADIATION REDUCTION RULE

摘要

PROBLEM TO BE SOLVED: To provide a circumferential circle center radiation reduction rule for grasping simply a far-away focus (VP) required for drawing an outer appearance perspective drawing on a small drawing desk. ;SOLUTION: An outer king wheel guide plate slide slit 2, a shaft supporting hole 3 and a circle center graduation 17 are provided on a circumferential ring wheel box 1, and an outer ring wheel 5 with an outer ring guide plate 8 on a shaft 4 and an inner ring wheel 6 are so fitted as to rotate coaxially, and the outer ring wheel 5 so fitted as to slide the shaft 4, and an outer ring wheel rotation hole 11, an inner ring wheel rotation hole 12, a radius fluctuation plate slide slit 10 and a graduation 16 are provided on a rule plate 9. The radius fluctuation plate 13 with a circumferential point hole 14 is fitted on the radium fluctuation plate slide slit 10 by a radium fluctuation plate slide fixing screw 15, and the shaft 4 with the outer ring wheel 5 and the inner ring wheel 6 is fixed on the shaft supporting hole 3 and the outer ring wheel guide plate slide slit 2 of the circumferential ring wheel box 1 by an outer ring wheel guide plate fixing screw 7, and the circumferential ring wheel box 1 on which the outer ring wheel 5 and the inner ring wheel 6 are fitted in conformity with the sections of the outer ring wheel rotation hole 11 and the inner ring wheel rotation hole 12 of the rule plate 9.;COPYRIGHT: (C)1999,JPO