| 摘要 |
Two portions (6, 7) of an extendible rod-like element (2a) are joined together in an adjustable manner by means of a device (10) with a external screw thread (11) and an internal screw thread comprising an internally threaded sector (12b) movable on one of the portions of the rod-like element from an operative position of engagement with the external screw thread (11), in which the portions are locked as regards relative sliding, to an inoperative position of disengagement from the external screw thread (11), in which the portions can slide freely relative to one another. In the operative position, the internally threaded sector (12b) can be rotated for a precise adjustment of the extension of the rod-like element (2a) whereas, in the inoperative position, it is possible to carry out an approximate and quick adjustment. <IMAGE> <IMAGE> |
