| 摘要 |
A pipe milling apparatus for milling away tubular casing encased within well bores has a tubular body (12) having at least two equi-circumferentially spaced longitudinal slots (14) formed through the circumferential wall of the body and a milling blade (40) radially extends through each slot, each milling blade having a longitudinally extending flange portion (42, 46, 47) inside the tubular body, the flange portion including a tab (46) for holding the blade within the tubular body. A radially inner surface (48) of each blade has a tapered surface for cooperating with a cylinderical mandrel (20) that is inserted into the tubular body, the mandrel having a taper corresponding to the taper on the blade such that the corresponding tapers frictionally abrade one another to wedge the blades radially outwardly of the tubular body. In a further embodiment of the invention two tapered rings are provided each having tapers for locating respective ends of a blade so that movement of the rings toward one another causes the blade to be moved radially outwardly. In such a further embodiment one of the rings is arranged to be flexible and the rings are biased toward one another by a compression spring. |
