| 摘要 |
<p>Appts comprises an internally threaded bush, with two threads of opposite hand, a sleeve or female screwdriver with drive lugs, rotationally fixed to a drive rod, but mobile in translation by means of a return spring system along the length of the rod. The appts is dismantlable and includes means for braking the rotation of the threaded bush wrt the outer sleeve and female attached to the guide tube, and devices for preventing rotation of the sleeve of the guide tube wrt the upper end plate, during fixing and dismantling. The zircalloy (RTM) guide tube can be fastened to the stainless steel upper end plates without welding or longitudinal slip.</p> |
