| 摘要 |
<p>PROBLEM TO BE SOLVED: To provide a combination ruler comprising short rulers that can be easily combined to securely make a long straight ruler in a combined form.SOLUTION: A combination ruler comprises a plurality of unit rulers 10 with the same shape and dimensions. Each unit ruler 10 is provided with a an internal gear-like recess 16 and an external gear-like protrusion 18 at each endpoint on a center line C of a longitudinal member 11 which has a readily portable short ruler shape with two parallel sides facing each other, and the number and size of the teeth are made equal to each other so that each can be removably fitted between the unit rulers. In addition, when the number of the internal gear-like recess portions 16 and the external gear-like protrusion 18 is an even number, the tooth shapes of the internal gear-like recess portion 16 and the external gear-like protrusion 18 on the center line C of the longitudinal member 11 are designed to be the tooth top and the tooth bottom, respectively, or the tooth bottom and the tooth top, respectively, so that the internal gear-like recess portions 16 and the external gear-like protrusions 18 of the unit rulers 10 can be fitted and combined in the same direction to make a long straight ruler.</p> |
