| 摘要 |
DRIVE FOR AUTOMATIC LANCE-CHANGING DEVICES The invention relates to a drive for an automatic lance-changing device, such as is used, for example, in steel by making the top-blowing process. Such a lance-changing device comprises two lance-receiving hooks pivotable about a horizontal axis of rotation, means for the synchronous vertical displacement of these hooks relative to the lance carriage and to the coupling head means which, during this displacement of the hooks, cause these to execute a pivoting movement about their said axis of rotation, and means for detecting by measurement the load acting on each hook , the latter being a function of the force with which the lance top part is pressed against said coupling head by the hooks. The drive of this invention is a lifting-spindle system, by means of which a vertically displaceable suspension ring for suspension hooks of the lance top part is driven. This lifting-spindle system consists of at least two tie rods the upper ends of which are equipped with an external movement thread, and of at least two gearwheels, the hubs of which are equipped with a corresponding internal movement thread for interaction with said upper ends . These gearwheels are mounted axially/radially in a gear case which itself rests on load cells . The latter cause the lifting-spindle drive to be switched off automatically when a predetermined pressure force between the lance top part and a coupling head is reached. Fig. 1
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