| 摘要 |
PURPOSE:To prevent a cylinder cover from falling off from a cylinder tube and turning, by fitting a ring key in both an external and an internal keyway and positioning the head part of a male screw in a hole. CONSTITUTION:An external keyway 4 and an internal keyway 6 are brought into coincidence with each other, and a tapped hole 5 is aligned with a hole 7. With this, a driver engages a slot 8c on a male screw 8 through the hole 7 and a notched part 9a to screw outwardly the male screw 8, which results in forcedly windening the notched part 9a in a ring key 9 by a shoulder part 8a of the male screw 8 to increase the size of the ring key 9. This causes the ring key 9 to be fitted and positioned in both the external keyway 4 and internal keyway 6, and brings a head 8b of the male screw 8 to be positioned in the hole 7. |
