| 摘要 |
A device in spindles to effect two different transfers of a screw and/or one or more bodies, whereby the screw (2) has two pitches (18, 19), as a coarse thread (6) for rapid transport and a fine thread (5, 7) for normal transport. A first and a second body (11, 12) are arranged to be able to be displaced relative to one another in the axial direction of the screw (2), whereby by changing the distance between the said bodies (11, 12) a changing from a first thread with one pitch to a second thread with another pitch can be done. Further, the body or bodies are mechanically guided in one of the threads by means of a ball. Such a ball is arranged into the said first body and into the said second body. On loading or on an increased loading on a body (11 or 12) the body changes from the one to the other thread (6 and 5, 7 respectively). When the other body (12 and 11 respectively) also gets a load or an increased load by the fact that it reaches the first body (11) the second body also changes from the said one thread (6) and to the said other thread (5, 7). When the load ceases on the bodies (11, 12) they return to the first thread (6) in reversed order, i.e. the second body (12 or 11) enters the first thread (6) and when the distance between the bodies (11, 12) increases to a distance, which is equivalent to a pitch of the first thread (6), the first body (11 and 12 respectively) can also change from the second thread (5, 7) to the first thread. |
