摘要 |
A new type of screw-and-nut mechanism comprises a supporting seat, one or more semi-nuts and the actuating means thereof, characterized in that the engagement of internal thread on the semi-nut with external thread on the screw is started elastically, then completed and locked by a positive element, and that the disengagement thereafter of the related elements is accomplished positively. Such a mechanism can be used in various kinds of jacks, vices, sliding tables of machine tools, as well as other devices which is driven by a screw and desired to pass through its return travel quickly. <IMAGE> |