| 摘要 |
A collapsible mandrel, having core and segmented collar, is collapsed and reassembled through rotating positioning means. The collar segments are divided in two groups, whereby the smaller segments have radially outwardly tapering surfaces for engagement with the respectively interspaced, larger segments. The rotating positioning means control radial displacement of the two groups of segments in sequential operation, either through appropriate camming and a single control ring, or through two, independently operated control rings. |
