| 摘要 |
<p>The expander comprises a tool which is basically cylindrical in shape and made up of a series of sector-shaped jaws (3), e.g. six in number, which are moved apart to expand the end of a pipe by means of a conical pin (15) inserted axially between them. After the pin has been retracted the jaws are returned to their initial, closed positions by internal springs. Each of the jaws has flat surfaces adjacent to its lateral faces, so that each of its outer corners is right-angled in shape.</p> |
