| 摘要 |
PURPOSE:To measure easily and accurately the position of a groove, by actuating the stylus of a dial gauge to extension and contraction which hits the inside end of a piston member according to positions of the end surface of the piston member and a collar part of the collet member admitted in the inside peripheral groove. CONSTITUTION:When a piston 7 of diameter centracting means is pressed, outside end of a piston member A is inserted into a hole engaged with a bearing cup 12 of a universal joint 9 by diameter centiacting of collet members 13 and 16, end surface 20 is allowed to rest against the head of the cup 12 and the main body 2 is pulled up after separating the piston 7 of the contracting means,the member 3 is pulled up with the main body 2 with the end surface 20 being pressed against the head of the cup 12 by a spring 5 force and the collar part 21 of the member 3 becomes engaged with the groove 13, allowing the top surface of the collar 21 to contact with the top surface of the groove 13. At this moment, a distance (t) between the end surface 20 and top surface of the collar 21 is replaced by a position relation ship of the inside end surface 25 of the member to the main body 2 and so, reading of a scale of a dial gauge 8 affords reading of a difference from the reference dimension set by the master blocks. |
