| 摘要 |
<p>PCT No. PCT/CH84/00072 Sec. 371 Date Jan. 11, 1985 Sec. 102(e) Date Jan. 11, 1985 PCT Filed May 11, 1984 PCT Pub. No. WO84/04447 PCT Pub. Date Nov. 22, 1984.A screw (22) having the circumference of its head (23) toothed like a pinion firmly holds the cylindrical shank of a rotary tool in position in a slotted sleeve (17). A rack (25) on the front end of the hollow cylindrical spindle (24) meshes with the pinion or head (23) of the screw (22). The retraction or advance of the rack (25) is effected by a grooved ring (20) through screws (35,36) whose cylindrical heads are engaged in two helical guide slots provided in a nosepiece (19) and which are anchored in a pusher ring (28) indirectly applied against the rear face of the hollow cylindrical spindle (24).</p> |
