| 摘要 |
PROBLEM TO BE SOLVED: To provide an inexpensive, easy-to-handle, and small-sized oval ruler, or a small-sized oval ruler set which contracts the size of the outer shape of an oval ruler and require no large space. SOLUTION: Oval hole sections 3 and 6 for which two oval holes are made a pair from among oval rulers of a certain degree, are crossed. In this case, a bridge 7 is provided in such a manner that the oval hole sections may not be omitted from a ruler board while ensuring respective right or left halves (or more than halves) of the oval hole sections 3 and 6. Also, to facilitate the recognition of the oval shapes by a worker, a partial oval hole section 8 is provided as long as a blank space permits.
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