| 摘要 |
<p>A tool for moulding a hollow profile which includes an internal undercut, uses a core tool with a plug made in two parts to accommodate an annular rib made of several segments. Some of the segments are keyed to sloping tracks which can be retracted, e.g. by a ram to shift the associated segments radially. Subsequent parting of the tool allows contact between tapered pins and oblique surfaces on the remaining rib segments, thus shifting the residual segments radially. Used for making a variety of undercut profiles of metal or plastics materials the core disengagement motion is rapid and uncomplicated, responding positively to a single platen traverse motion to release and shift both sets of the tool segments. The wedges and the pins are picked up at different stages of the platen motion.</p> |
