| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide an effective diameter measurement instrument capable of measuring an effective diameter of a female screw with a high reliability. <P>SOLUTION: The effective diameter measurement instrument 1 for measuring an effective diameter of a female screw 100 includes: a first measurement unit 2A which has tip spheres 21b and 21b to be fitted into a thread groove 101 on one side in an inner diameter part of the female screw 100; a second measurement unit 2B which has a tip sphere 24b to be fitted into a thread groove 101 on the other side located in a position opposite to the thread groove 101 of the one side with a shaft center of the female screw 100 therebetween; and a clamp unit 3 which holds a measurement attitude of the female screw 100 while supporting the first measurement unit 2A and the second measurement unit 2B so that they can be moved toward and away from each other. The tip spheres 21b, 21b, and 24b of the first measurement unit 2A and the second measurement unit 2B are supported so as to be movable toward the shaft center of the female screw 100 by the first measurement unit 2A and the second measurement unit 2B respectively. <P>COPYRIGHT: (C)2012,JPO&INPIT |
