Patent ID: 6966728

Claim:
A toolholder assembly for releasably holding a toolholder, the toolholder assembly comprising: a tool support member having a forwardly facing surface and a bore along a longitudinal axis and a passageway along a radial axis (R 1 ), the passageway extending through the tool support member and the bore intersecting the passageway and the forwardly facing surface and extending rearwardly from the forwardly facing surface for receiving the toolholder, the passageway having a first aperture and a second aperture wherein the first aperture and the second aperture include at least two forward wall surfaces; an actuating bolt positioned within the passageway and having a first end with a bolt locking segment having a side surface and a bolt locking surface; and an actuating centering nut rotatably fixed within the tool support member and threadably secured to a second end of the actuating bolt, the actuating centering nut having a centering nut locking segment having centering nut locking surfaces including two side surfaces; wherein during locking of the actuating bolt with the toolholder, the actuating centering nut is drawn to the bolt first end thereby forcing at least the forward wall surfaces and the actuating bolt side surface and the centering nut side surfaces to engage in at least single point contact on each side of the radial line (R 1 ) equidistance from the radial line (R 1 ) to center the actuating centering nut and the actuating bolt and the toolholder with respect to the radial axis of the bore.