摘要 |
METHOD AND APPARATUS FOR LOCATING AND CLAMPING A WORKPIECE, SUCH AS A PISTON, PRIOR TO ROTATING SAME IN A MACHINING OPERATION A method and apparatus for locating and clamping a piston (10, 110) between headstock and tailstock assemblies (18, 118 and 20, 120) before rotating same about a rotary axis (22, 1223 in a machining operation is characterized by an equalizing mechanism or member (So, 150) for equalizing the axial force between a pair of equalizing pins (48, 148) of a first set of axially extending locating pins (46, 48; 146, 148) to thereby create a locating plane on a first surface of the workpiece. The first set of axially extending pins coacts with a second set of axially extending equalizing pins (30, 130) to clamp the workpiece therebetween. The first set of locating pins are located in a housing member (38, 138). The first set of pins also includes two fixed locating pins (48, 148) which contact the outer surface of the piston. The second set of axially extending pins includes four equalizing driving pins (30, 130) which contact the inner surface of the piston directly opposite the four locating pins of the first set at non-colinear points radially spaced about the rotary axis. Preferably, a centering member (52) also housed in the housing member is provided for centering the piston about the rotary axis. |