Patent ID: 7144355

Claim:
A tool replacement method, comprising: positioning a spindle relative to a nut driving station wherein the nut driving station comprises a forward nut driver and a reverse nut driver, each of the forward nut driver and the reverse nut driver having a respective forward-rotating or reverse-rotating nut driver and a unidirectional spindle rotation preventor axially aligned with each other, wherein each of the forward nut driver and reverse nut driver is resiliently supported in a rotary mount mounted to the nut driving station for rotation a nut of the spindle; positioning a receiving hole of a tool holding jig substantially in alignment with a tool associated with the spindle; engaging the spindle and the nut with the unidirectional spindle rotation preventor and the reverse-rotating nut driver respectively; rotating the nut relative to the spindle to loosen a chuck of the spindle; transferring the tool holding jig from the spindle to a tool post; engaging the spindle and the nut with the spindle rotation preventor and with the forward-rotating nut driver respectively; positioning a replacement tool substantially within the chuck of the spindle; and rotating the nut relative to the spindle to tighten the chuck of the spindle.