| 摘要 |
<P>PROBLEM TO BE SOLVED: To solve a problem in conventional techniques wherein prevention of looseness between a shaft cylinder and a tip cylinder, that is, fixation is performed in an unscrewing rotating direction and thus, due to regulation only by screw threads of screwing parts, pulling to a connecting direction of the shaft cylinder to separate the shaft cylinder and tip cylinder may cause one screw thread to ride over the other screw thread, leading to easy detachment of the shaft cylinder and the tip cylinder. <P>SOLUTION: A shaft cylinder is constituted by interconnecting a first shaft cylinder and a second shaft cylinder by screwing, and engagement parts engaged when the screwing is completed are provided in the shaft cylinders, respectively. A surface part vertical to the connecting direction is formed on the side where the engagement parts are engaged. <P>COPYRIGHT: (C)2012,JPO&INPIT |
