Novel teaching compass

Abstract

The invention discloses a novel teaching compass. The novel teaching compass is composed of a movable compass foot and a stationary compass foot. The lower end of the movable compass foot is provided with a chalk holder and the lower end of the stationary compass foot is a suction foot formed by a sucker, a rotary bead and a rotary bead seat. The sucker is fixed on the rotary bead clamped in the rotary bead seat. The novel teaching compass has following beneficial effects: the novel teaching compass is simple in structure, easy in manufacture, reliable in performance and quick in drawing and is particularly suitable for drawing circles on a blackboard, a wall surface and all hard board surfaces.

Description

technical field [0001] The invention belongs to the class of teaching instruments, and relates to a novel teaching compasses. Background technique [0002] The compasses widely used in teaching at present are made up of dynamic gauge pin and static gauge pin. There is a chalk chuck at the lower end of the dynamic gauge foot, and the positioning pile is at the lower end of the static gauge foot. When drawing, the point positioned by the static gauge foot positioning stake on the blackboard is the center of the circle. Because the positioning stakes and the blackboard are both hard materials, the positioning stakes are very easy to slip on the blackboard and cause displacement in the drawing, so that the drawings made are irregular or even impossible to draw. Contents of the invention [0003] The purpose of the invention is to develop a teaching compasses whose static gauge foot positioning pile cannot slip on the blackboard. [0004] The technical scheme for realizing t...

AI Technical Summary

Problems solved by technology

Since the positioning stakes and the blackboard are both hard materials, the positioning stakes are very easy to slip on the blackboard and cause displacement during the drawing, so that the drawing is irregular or even impossible to draw.

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