Blurring of drafting hetsudo - ki device

摘要

PURPOSE:To reduce operation force by enhancing braking force and to facilitate processing and assembling by providing the brake disc integrally revolving along with a protraction disc and providing the brake holding the vicinity of the outer edge part of the brake disc between a support plate and a scale mounting plate under pressure to form a base line brake mechanism and an arbitrary angle brake mechanism. CONSTITUTION:When a base line brake lever 71 is revolved in the direction on this side, a left screw 67 is revolved leftwardly by the actions of a main driving sector gear 69 and a passive sector gear 68 to be screwed in a brake shoe 65. Since the leading end part of the left screw 67 is in contact with the stopper screw 72 screwed in a support plate 51, the rear part of the brake shoe 65 is raised upwardly and shaken around a sector pin 64 and the front end part 65a of the brake shoe brings the brake disc 59 into contact with a fixed brake shoe 66 under pressure to stop the revolution of the brake disc 59 and a protraction disc 58. When an index level 74 is revolved in the direction on this side, the brake shoe 59 is brought into contact with the fixed brake shoe 82 under pressure by a leading end region 80a and a scale mounting plate 53 can be fixed at an arbitrary angle with respect to the protraction disc 58.