摘要 |
<p>The blank is driven over the mandrel in a piercing rolling mill, and then both are moved sideways out of the rolling axis to an extractor, in which a clamping head draws the mandrel out of the pierced blank. The pierced blank is next removed sideways, whereas the mandrel enters a cooling basin and is then moved sideways onto a roller track (a). Roller track (a) is employed to drive the mandrel forward into a position parallel with the rolling axis, and from which the mandrel is returned to its working position. One mandrel can thus be cooled and return to its working position while another mandrel is piercing another tube blank. Continuous circulation is achieved of mandrels which are cooled, inspected, and re-used. Min. loss of productive time is achieved.</p> |