| 摘要 |
An arbor for an annular hole cutter wherein a resiliently compressible sleeve is connected to a central pilot pin in the cutter and is expanded radially into tight frictional contact with the bore of the arbor so that a compression spring which biases a pointed pilot pin axially outwardly at the center of the cutter and compresses progressively as the cutter penetrates into the work will expand slowly by reason of said frictional contact and the slow recovery rate of the compressible sleeve when the cutter penetrates through the under surface of the workpiece. |
