Compasses

Abstract

The invention relates to a pair of compasses, of which two legs (3 / 4) are rotatably installed on a central drive unit (5) and provided with an operation body rotatable around the longitudinal axis. The pair of compasses provided in the invention enables conveniently drawing circles or arcs.

Description

technical field [0001] The present invention relates to compasses. Background technique [0002] general compasses, such as Figure 6 Shown all have the central support foot 3 that steel needle 6 is housed and the pen holder rotating foot 4 that pencil 14 is housed and the middle drive that two pin 3 / 4 free opening and closing are connected, on the middle drive, the gauge that pinches with finger is housed Head 38. And, when drawing a circle or arc (hereinafter referred to as circle, etc.), for example: Figure 6 As shown, the two pins 3 / 4 of opening can be fixed on the paper, and the gauge head 38 can be rotated with fingers. In addition, Patent Document 1 (Patent Kaiping No. 10-193877) also lists the compasses that are provided with the operating portion on the middle drive. [0003] The above-mentioned rotation of the operating portion 38 when drawing a circle or an arc is divided into 2 kinds: the one is the revolution that rotates around the steel needle 6 fixed on th...

AI Technical Summary

Problems solved by technology

In addition, when the operation part 38 rotates, it is necessary to rotate the operation part 38 between several fingers. This kind of operation is more difficult for the handicapped or schoolchildren with small palms, even for adults or healthy people. That said, it can also be a burden in situations such as cartography where several circles or arcs need to be drawn

Especially when drawing small-diameter circles or arcs, it is necessary to reduce the revolution diameter of the operation part 38 so that the operation part 38 can rotate between small revolutions, which makes the operation particularly difficult.

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