| 摘要 |
<p>Apparatus for and method of clamping on the inner surface of a clamping aperture to journal a rotatable tooling bar, in paricular to provide air bearing support for a rotatable tooling bar (14) such as a boring bar, are described. One or two mandrels (12, 13) may be provided for the tooling bar (14) to form a complete mandrel assembly with the tooling bar. An air pressure expansible collet (52) is provided on each mandrel (12, 13) so that each may be clamped within a respective clamping aperture (15, 16) such as an aperture on a workpiece (17) itself. Air under pressure is supplied to the two mandrels (12, 13) simultaneously to accomplish, first, an air bearing centering of each mandrel (12, 13) around the tooling bar (14) as a guide; second, an expansion of the collet (52) on each mandrel for clamping of each mandrel within the clamping apertures; and, third, provision of an air bearing support and centering of the tooling bar (14) within the two mandrels (12, 13) during machining for precise machining of the workpiece (17) by the continued air supply.</p> |
